Doc #140 — Coastal Trading Network

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RECOMMENDED ACTIONS (BY URGENCY)

First month:

1. Inventory all NZ vessels with cargo-carrying potential through the national census (Doc #8) — fishing vessels, barges, commercial craft, large yachts, traditional waka. Separately flag all sailing-capable vessels.
2. Identify all usable ports and harbours, including those without modern infrastructure — wharves, jetties, boat ramps, sheltered anchorages
3. Appoint a coastal shipping coordinator within the national logistics framework

First 3 months:

4. Begin ad hoc cargo movements using available powered vessels — prioritize medical supplies, agricultural inputs, and industrial consumables to regions poorly served by road. This uses fuel, but less per tonne than trucking the same cargo.
5. Establish temporary fuel allocations for essential coastal shipping (Doc #53) — framed explicitly as a bridge measure, not a permanent operating model
6. Begin identifying and converting offshore-capable sailing vessels for cargo — widen hatches, remove excess accommodation, fit lashing points and deck cargo capacity
7. Begin sail handling training for powered-vessel crews — drawing instructors from the yacht racing, cruising, and traditional waka communities

First year:

8. Establish regular scheduled services on the primary coastal routes (Section 4) — using powered vessels initially, with sailing vessels added as they become available
9. Develop cargo handling systems for ports without cranes — derricks, A-frames, manual winches
10. Train additional crew — draw from fishing, yachting, and Navy communities, with emphasis on sail competence alongside powered-vessel operation
11. Begin construction of purpose-built coastal cargo sailing vessels (Doc #138, #141)

Years 1–3:

12. Progressively shift from powered to sail-primary coastal services as fuel depletes and sailing crew and vessels become available
13. Integrate coastal shipping schedules with road and rail transport for inland distribution
14. Establish a weather routing and communication system using HF radio (Doc #128)

Years 3+:

15. Expand network to include smaller harbours and remote communities
16. Full transition to sail-powered coastal fleet — powered vessels retained only for Cook Strait and emergency use if any fuel remains
17. Integrate with Tasman and Pacific trade routes (Doc #142)

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ECONOMIC JUSTIFICATION

The problem coastal trading solves

NZ’s domestic freight system moves approximately 260 million tonnes per year, of which roughly 93% travels by road.³ This system depends entirely on imported diesel, tires, and vehicle parts. Under the recovery scenario, road freight capacity declines as fuel is rationed (Doc #53) and tires deplete (Doc #33). Rail handles some freight but reaches limited areas — NZ’s rail network serves the main trunk routes but not the West Coast of the South Island, much of the East Cape, Northland beyond Whāngarei, or the Coromandel.⁴

While fuel lasts, coastal shipping uses less of it per tonne-kilometre than road transport — approximately 5–15 grams of fuel per tonne-km for a small coastal vessel versus 25–50 grams for a truck.⁵ This efficiency advantage justifies allocating some fuel to coastal shipping during the transition. But fuel efficiency is not the long-term argument for coastal trading — the long-term argument is that sailing vessels move cargo with no fuel at all. Under sail, the operating cost is crew time, vessel maintenance, and schedule flexibility. Speed and reliability decline compared to powered vessels, but the service continues indefinitely.

Person-years and cost

Establishing the coastal trading network requires:

• Network coordination and port assessment: 5–10 person-years in Year 1 (port surveys, scheduling, communications infrastructure)
• Vessel conversion: 10–20 person-years in Years 1–2 (fitting cargo holds, installing derricks, modifying fishing vessels)
• Crew training: 5–10 person-years ongoing (navigator training, cargo handling, sail training)
• Port infrastructure at secondary harbours: 10–30 person-years in Years 1–3 (wharf repair, installing manual cargo handling equipment, building storage)
• Total: approximately 30–70 person-years over the first 3 years

These person-years are not equally scarce. Navigator training and vessel conversion require specialist maritime skills — experienced fishers, merchant mariners, boatbuilders — who are in limited supply. Port infrastructure work and cargo handling, however, are semi-skilled construction and manual labour that can be staffed from the broadly available workforce of people displaced from disrupted industries.

What it replaces

Without coastal shipping, goods must travel by road or rail. As road transport declines:

• The West Coast of the South Island becomes increasingly isolated — the road over Arthur’s Pass or through the Buller Gorge is the only connection, and both are vulnerable to weather and landslips
• Northland communities beyond the rail terminus become dependent on a single highway
• The East Cape and Gisborne region, already remote by road, faces supply difficulties
• Cook Strait crossings — currently handled by the Interislander and Bluebridge ferries — depend on maintaining those vessels or finding alternatives
• Island communities (Great Barrier, Chatham Islands, Stewart Island) lose their lifeline

Breakeven

The investment breaks even when coastal shipping prevents the isolation of one or more regions that would otherwise lose reliable supply. Given NZ’s geography — long, narrow, with mountain ranges dividing east from west — this point is reached quickly. The West Coast alone has a population of approximately 32,000 people who become largely dependent on sea access once road transport declines.⁶

The relocation alternative

Not every isolated community should be supplied by sea. For some small, remote settlements, the honest answer is that the cost of maintaining a supply chain — whether by road, rail, or coastal shipping — exceeds the value of keeping that settlement populated. This is especially true for communities that were economically dependent on industries that no longer function (tourism, export-oriented aquaculture, mining operations that required imported equipment).

Encouraging voluntary relocation to larger towns with better transport connections may be more practical than building coastal trading routes to serve a few hundred people. This is socially difficult — people are attached to their communities, and forced relocation has a grim history — but the alternative is communities slowly declining as supplies become unreliable and younger residents leave anyway. Planned, supported relocation (with housing, employment, and community integration at the destination) is better than unplanned abandonment.

The calculus is case-by-case. A West Coast town of 3,000 people with a usable harbour, local agriculture, and timber resources is worth connecting by sea. A remote settlement of 150 people accessible only through a deteriorating road, with no harbour and no local productive capacity beyond what they consume, may not be. Population planning (Doc #155) and workforce reallocation (Doc #145) should inform these decisions, which ultimately require local government input and honest community consultation.

Coastal trading network planning should identify which communities are viable to supply and which are not — and route design should reflect this assessment rather than attempting to serve every settlement that previously received road freight.

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1. NZ’S COASTAL GEOGRAPHY AND EXISTING INFRASTRUCTURE

1.1 Port hierarchy

NZ has 13 commercial ports handling international and domestic cargo, plus dozens of smaller harbours, fishing ports, and coastal facilities.⁷ For coastal trading purposes, these can be organized into tiers:

Tier 1 — Major ports (deep water, cranes, fuel, rail connection):

• Auckland (Ports of Auckland) — NZ’s largest port, Hauraki Gulf access
• Tauranga (Port of Tauranga) — NZ’s largest export port by volume, Bay of Plenty
• Wellington — Cook Strait hub, central NZ
• Lyttelton — Canterbury’s port, rail tunnel to Christchurch
• Port Chalmers (Otago) — Dunedin’s port
• Napier — Hawke’s Bay
• New Plymouth — Taranaki
• Nelson — Top of the South Island
• Bluff — Southland, access to Stewart Island and sub-Antarctic

Tier 2 — Secondary ports (operational but limited infrastructure):

• Whāngarei (Marsden Point) — Northland, refinery site
• Gisborne — East Cape
• Timaru — South Canterbury
• Greymouth — West Coast
• Westport — West Coast
• Picton — Marlborough Sounds, current ferry terminal

Tier 3 — Minor harbours and anchorages (usable for small vessels):

• Whāngārei Heads, Mangōnui, Opua, Russell (Bay of Islands)
• Whitianga, Thames, Tairua (Coromandel)
• Ōpōtiki, Whakatāne (Bay of Plenty)
• Wairoa, Tolaga Bay (East Coast)
• Whanganui, Foxton (West Coast North Island)
• Kaikōura, Akaroa (Canterbury coast)
• Oamaru (North Otago)
• Riverton, Te Waewae Bay (Southland)
• Hokitika, Jackson Bay (West Coast South Island)
• Motueka, Havelock (Marlborough/Tasman)
• Chatham Islands, Great Barrier Island, Stewart Island (offshore communities)

1.2 Harbour depths and vessel constraints

Many Tier 3 harbours are shallow, tidal, or bar-harbours — navigable only at certain tidal states and by vessels with shallow draft. Greymouth and Westport both have bar entrances that are dangerous in heavy swell.⁸ This constrains vessel selection: coastal traders serving smaller ports need shallow draft (under 2 metres), and schedules must account for tidal access windows.

NZ coastal pilots (Doc #13) provide detailed approach and depth information for all harbours. Printed copies of these guides should be aboard every coastal trading vessel.

1.3 Existing wharf and jetty infrastructure

Most Tier 1 ports have container cranes and modern cargo handling that will remain functional while electricity and maintenance continue. But many Tier 2 and 3 harbours have only basic wharves or jetties — adequate for tying alongside but with no mechanical cargo handling. Some historical wharves have deteriorated and require assessment before use.

The cargo handling problem at small ports is addressed in Section 5.

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2. AVAILABLE VESSELS

2.1 NZ’s existing fleet

NZ’s maritime fleet includes several categories of vessels that can carry cargo:⁹

Commercial fishing vessels (~1,200 registered commercial fishing vessels): These are NZ’s most immediately useful coastal cargo fleet. Fishing vessels are designed for sea conditions, have cargo holds (fish holds that can carry general cargo), powered winches for loading, and experienced crews. A typical NZ inshore fishing vessel of 12–20 metres can carry 5–20 tonnes of cargo. Larger deepwater vessels (20–40+ metres) can carry substantially more but are fewer in number. The fishing fleet is distributed around NZ’s coast, with concentrations at Nelson, Tauranga, Auckland, Timaru, and Bluff.

Trade-off: Vessels used for cargo are not fishing. Fisheries management (Doc #82) and coastal trading must share the fleet. In practice, many vessels can alternate — fishing on some trips, cargo on others — and the seasonal nature of some fisheries allows reallocation during off-seasons.

Yachts and recreational sailing vessels: NZ has an estimated 10,000–15,000 recreational sailing vessels, of which perhaps 1,000–3,000 are offshore-capable keelboats of 9 metres or larger.¹⁰ Most are not designed for cargo — they have deep keels, small hatches, and accommodation-focused interiors. However, some can be modified for light cargo (1–5 tonnes), and their sailing capability is valuable as fuel depletes. Larger yachts (12+ metres) with deck cargo capacity are more useful.

Performance gap: Converted yachts carrying 1–5 tonnes represent a 75–95% reduction in cargo capacity compared to a 20-tonne fishing vessel, and passage times under sail are typically 2–4 times longer than under power (see Section 4 route tables). Schedule reliability also declines — sailing vessels cannot guarantee arrival times because they depend on wind conditions, whereas powered vessels can hold schedules in most weather. This performance gap means converted yachts supplement rather than replace powered cargo vessels; purpose-built sailing cargo vessels (Section 2.3) are needed to close the gap.

Barges and work boats: NZ has harbour barges, mussel farm vessels, and general work boats, particularly around the Marlborough Sounds, Hauraki Gulf, and major ports. These are flat-bottomed, high-capacity (10–100+ tonnes), but generally not designed for open-sea passages. They are valuable for sheltered-water routes: Hauraki Gulf, Marlborough Sounds, harbours, and short coastal runs in settled weather.

Inter-island ferries: The Cook Strait ferries (currently operated by KiwiRail’s Interislander and StraitNZ’s Bluebridge services) are NZ’s most critical coastal link, carrying passengers, vehicles, and freight between Wellington and Picton. These vessels are diesel-powered and fuel-intensive — a single Cook Strait crossing consumes approximately 5–15 tonnes of marine diesel depending on vessel size, loading, and sea conditions.¹¹ Maintaining at least one ferry in service for as long as fuel allows is a high priority, but planners should not assume this lasts more than 1–3 years given competing fuel demands (Doc #137). The Cook Strait crossing under sail is feasible (the strait is approximately 22 km at its narrowest, though the shipping route through Tory Channel is longer) but slower and far lower-capacity — purpose-built Cook Strait sailing vessels should be among the first new-build priorities (Doc #137).¹²

RNZN and government vessels: The Royal New Zealand Navy’s inshore and offshore patrol vessels, and survey vessels, have cargo and passenger capacity. Maritime NZ and other government agencies operate additional vessels. These will likely be allocated to priority missions but represent available maritime capability.

Waka and traditional Māori vessels: Waka hourua (double-hulled ocean-going canoes) are capable open-ocean vessels with cargo capacity. Several exist in NZ and the knowledge to build more is actively maintained within Māori communities. Waka tētē (single-hull sailing canoes) are suitable for coastal and harbour work. Integration of traditional Māori maritime knowledge and vessel types into the coastal network should be pursued in partnership with iwi.¹³

2.2 Vessel conversions

Fishing vessels require minimal conversion for cargo work — their holds already accept bulk cargo, and their crews know the sea. The main modifications are:

• Securing points for cargo: Ringbolts, lashing points, bulkhead reinforcement to prevent cargo shift
• Weather protection: Hatch covers, tarpaulins for deck cargo
• Cargo handling: Many fishing vessels have hydraulic or powered winches; these can be adapted for cargo operations. Where not available, manual derricks or A-frames can be fitted.
• Navigation: Ensure charts, coastal pilot guides, and tide tables are aboard (Docs #10–13)

Yacht conversions are more involved. Removing interior accommodation to create cargo space, strengthening decks for cargo weight, widening hatches, and fitting cargo handling gear. This work requires: marine-grade timber or plywood for structural reinforcement (NZ-grown radiata pine or locally milled kauri where available); stainless steel or galvanized fasteners (from existing stock — NZ does not manufacture stainless steel fasteners domestically); fibreglass and epoxy resin for hull repairs (both are imported petrochemical products with finite NZ stocks; no near-term domestic substitute for fibreglass mat exists); and skilled boatbuilders for structural assessment and modification. Polyester resin is sometimes described as producible from NZ biomass feedstocks, but the production chain — bio-derived glycols and phthalic anhydride, requiring chemical plant infrastructure not currently present in NZ — makes domestic production a multi-year Phase 4+ project rather than a near-term fallback.¹⁴ In practice, hull repair during Phases 2–3 depends on drawing down existing resin stocks; vessels with structurally sound hulls requiring minimal fiberglassing should be prioritised for conversion. NZ’s approximately 50–80 boatyards and marine service facilities have the skills and most of the tooling required, but conversion throughput declines as fastener and resin stocks deplete.

2.3 New-build vessels

Purpose-built coastal cargo sailing vessels should begin construction in Phase 2–3. Doc #138 addresses design and Doc #141 addresses construction techniques. For coastal trading specifically, the key design parameters are:

• Shallow draft (under 2 metres) for access to Tier 3 harbours
• Flat or shallow-vee bottom for sitting on tidal flats and beaching for loading where no wharf exists
• Cargo capacity of 10–40 tonnes for coastal routes
• Sail rig optimized for NZ coastal conditions — variable winds, need to make progress to windward, frequent short passages
• Crew of 2–4 — labour is scarce

The Thames sailing barge model referenced in Doc #138 is relevant: flat-bottomed vessels that carried 80–200 tonnes with a crew of two in the Thames estuary and English east coast.¹⁵ NZ coastal conditions are substantially more exposed than the Thames — the Southern Ocean swell, Cook Strait, and the West Coast bar harbours demand significantly greater freeboard, deck reserve buoyancy, and robust sail-reduction ability than estuary trading barges required. A direct Thames-barge design adapted without modification would be inadequate for the South Island coast and Cook Strait in deteriorating weather. Purpose-built NZ vessels should follow the shallow-draft, flat-bottom, small-crew design principles but with heavier scantlings, higher freeboard, and a more easily shortened rig than the traditional spritsail. Doc #138 addresses NZ-specific design requirements.

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3. CARGO TYPES AND PRIORITIES

3.1 What moves by coastal shipping

Not everything needs to travel by sea. Coastal shipping is most valuable for:

High priority — goods that are heavy, bulky, or regionally concentrated:

• Steel and metal products from Glenbrook (Doc #89) to the rest of NZ — steel is heavy and currently travels by road and rail
• Cement from Golden Bay (Doc #97) — NZ’s cement works are at Portland (Whāngarei) and Golden Bay; distribution to the rest of NZ is a natural coastal shipping task
• Timber from forestry regions (Bay of Plenty, Gisborne, Northland, West Coast) to construction and boatbuilding sites
• Coal from the West Coast to industrial users — NZ’s remaining coal use is primarily industrial and concentrated on the West Coast
• Salt from coastal salt works (Doc #103) — bulk cargo
• Fertilizer — rock phosphate from existing NZ deposits, lime from coastal sources
• Fuel redistribution from bulk storage sites

Medium priority — essential supplies for remote regions:

• Medical supplies to communities distant from hospitals (East Cape, West Coast, offshore islands)
• Agricultural inputs — seeds, tools, fencing materials
• Manufactured goods — machine parts, tools, wire, nails from production centres to distributed users

Lower priority (but economically important):

• Food redistribution — moving surplus from producing regions to population centres. Pastoral production is distributed but processing is concentrated; coastal shipping can move preserved meat, dairy products, and grain
• Wool and hides from farming regions to processing centres

3.2 Cargo by route

Different routes serve different cargo mixes (see Section 4 for route descriptions):

Route	Primary northbound/eastbound cargo	Primary southbound/westbound cargo
Auckland–Northland	Consumer goods, manufactured supplies, food (partial load; low northbound demand)	Timber, coal (residual), agricultural products
Auckland–Tauranga–Gisborne	Steel, manufactured goods	Timber, food, wool
Wellington–Picton (Cook Strait)	Everything — NZ’s critical inter-island link	Everything
Nelson–West Coast	Manufactured goods, medical supplies, food	Coal, timber, gold (future?)
Lyttelton–Timaru–Oamaru–Dunedin	Steel, manufactured goods	Grain, wool, meat
Bluff–Stewart Island	Everything (lifeline service)	Fish, crayfish

3.3 Packaging and cargo handling for small vessels

Modern container shipping uses standardized 20-foot and 40-foot containers. Coastal trading vessels — particularly converted fishing boats and sailing vessels — cannot handle containers. Cargo must be broken down into units that can be manhandled or handled with a small derrick:

• Maximum individual unit weight: 50–200 kg (depending on vessel crane/derrick capacity; manual handling limited to approximately 25 kg per person)
• Sacks, barrels, crates, and pallets are the appropriate packaging — the same formats used in coastal shipping for centuries before containerization
• Bulk cargo (coal, salt, sand, grain) loaded by bucket, chute, or small conveyor where available
• Timber bundled and loaded as deck cargo — traditional practice
• Liquids in barrels or drums — steel drums (200-litre) are reusable; NZ imports large quantities for industrial and fuel use and significant numbers will be in circulation at the start of the recovery period, though the total available stock requires census verification (Doc #8)

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4. ROUTE NETWORK

4.1 Primary routes

Route 1: Auckland–Whāngārei–Bay of Islands–Auckland (Northland circuit) Distance: approximately 350–500 km depending on stops.¹⁶ Passage time under power: 1–2 days. Under sail: 2–5 days. Ports: Auckland, Whāngārei (Marsden Point), Opua/Russell, Mangōnui. Conditions: Generally sheltered inside the Hauraki Gulf; open coast from Bream Head to Cape Brett; Bay of Islands is well-sheltered. Prevailing winds SW–W. The Northland east coast is exposed to NE swells. Frequency: Weekly service from Auckland; twice-monthly to outer Bay of Islands ports.

Route 2: Auckland–Tauranga–Gisborne–Napier (East Coast North Island) Distance: approximately 600–800 km one-way.¹⁷ Passage time under power: 2–3 days. Under sail: 4–8 days. Ports: Auckland, Tauranga, Whakatāne, Ōpōtiki, Gisborne, Napier. Conditions: Open coast. East Cape is exposed — the stretch from Ōpōtiki to Gisborne is one of NZ’s more demanding coastal passages, with limited shelter. Prevailing winds are variable; NE in summer, W–SW in winter.¹⁸ Frequency: Fortnightly; more frequent Tauranga–Auckland segment.

Route 3: Wellington–Picton (Cook Strait) Distance: approximately 92 km (Wellington–Picton via Tory Channel). Passage time under power: 3–4 hours. Under sail: 4–12 hours depending on conditions. This is NZ’s most critical single link. Cook Strait is notoriously rough — strong tidal streams (up to 4–5 knots through the narrows), funnel winds, and short steep seas.¹⁹ The strait is navigable by sailing vessels but requires experienced crews, appropriate weather windows, and tide-aware passage planning. Frequency: Daily while powered vessels operate; at least 3–4 times weekly under sail (weather permitting).

Route 4: Nelson–Westport–Greymouth–Hokitika (West Coast South Island) Distance: approximately 350–450 km one-way.²⁰ Passage time under power: 1–2 days. Under sail: 3–6 days. Ports: Nelson, Westport, Greymouth, Hokitika. Conditions: The West Coast is NZ’s most exposed coastline — prevailing westerlies, large swells from the Southern Ocean, bar harbours at Westport and Greymouth that are dangerous in heavy swell.²¹ This route requires robust vessels, experienced crews, and weather-dependent scheduling. It is also the route where coastal shipping is most needed — the West Coast has no rail and limited road connections. Frequency: Weekly in summer; fortnightly in winter (weather dependent).

Route 5: Lyttelton–Timaru–Oamaru–Port Chalmers–Bluff (East Coast South Island) Distance: approximately 500–600 km one-way.²² Passage time under power: 2–3 days. Under sail: 4–8 days. Ports: Lyttelton, Timaru, Oamaru, Port Chalmers (Dunedin), Bluff. Conditions: Generally less exposed than the West Coast but open to southerly swells. Kaikōura coast is steep-to with limited shelter. Foveaux Strait (to Stewart Island) has strong tides and can be rough.²³ Frequency: Weekly.

Route 6: Wellington–New Plymouth–Auckland (West Coast North Island) Distance: approximately 650–800 km.²⁴ Passage time under power: 2–3 days. Under sail: 4–8 days. Ports: Wellington, Whanganui (river bar — difficult), New Plymouth, Auckland. Conditions: Cook Strait exit, then open Tasman Sea coast. The stretch from Wellington to New Plymouth is exposed with limited shelter. New Plymouth’s port is open to NW swells. Frequency: Fortnightly.

4.2 Lifeline services

Some routes serve communities that have no alternative supply chain:

• Bluff–Stewart Island (Halfmoon Bay): Population approximately 350–450.²⁵ Currently served by ferry and air. Under sail: 30–40 km across Foveaux Strait, 2–6 hours. Must be maintained at minimum weekly.
• Auckland–Great Barrier Island: Population approximately 900–1,100.²⁶ Approximately 90–100 km depending on departure point and anchorage, 6–12 hours under sail. Weekly.
• Chatham Islands: Population approximately 550–650.²⁷ 800 km east of NZ — a significant open-ocean passage of 3–7 days under sail. Monthly at minimum.

4.3 Scheduling principles

• Weather windows: No vessel should be forced to sail in unsafe conditions to meet a schedule. Schedules are targets, not commitments. The West Coast and Cook Strait routes will have weather-related delays built into planning.
• Tidal access: Ports with bar entrances or tidal constraints require tide-aware scheduling. Arrival and departure times are set by the tide, not the clock.
• Seasonal variation: Longer passages and more weather days in winter. Summer schedules can be more frequent.
• Communication: HF radio (Doc #128) provides weather information, vessel tracking, and schedule coordination. Every coastal trading vessel should carry HF radio.

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5. CARGO HANDLING AT SMALLER PORTS

5.1 The problem

Modern ports use container cranes, forklifts, and heavy machinery. Smaller harbours have none of this. Loading and unloading cargo at a Tier 3 harbour requires methods that work with minimal infrastructure.

5.2 Solutions (all proven historical methods)

Vessel-mounted derricks and booms: A swinging boom (a spar attached to the mast or a dedicated cargo post) with a block-and-tackle or small winch can lift 200–1,000 kg depending on design. Every coastal trading vessel should carry this capability. Fishing vessels with hydraulic cranes already have it.

Shore-based A-frames and sheer legs: Two or three timbers lashed together at the top with a block and tackle. Can handle 500–2,000 kg depending on timber size. Portable enough to move between sites. Construction requires: straight hardwood timbers of 150–250 mm diameter and 4–6 metres length (NZ-grown eucalyptus, macrocarpa, or treated radiata pine); steel shackles and blocks (from existing marine hardware stock or fabricated from NZ steel); and rope rated for the working load — synthetic rope from existing stock performs best, but harakeke (flax fibre) cordage (Doc #100) can substitute at approximately 40–60% of the working load capacity of equivalent-diameter nylon.²⁸

Manual handling: For smaller cargo (under 25 kg per unit), direct hand-loading is practical. A chain of 6–10 workers can load or unload approximately 2–5 tonnes per hour depending on unit weight, stacking distance, and wharf layout — significantly slower than mechanized handling (which achieves 20–50+ tonnes per hour with a single crane operator), but requiring no equipment beyond human labour.²⁹ Sacks, crates, and small drums are designed for this.

Beaching and drying out: Flat-bottomed vessels can be beached at high tide, loaded or unloaded as the tide drops, and refloated on the next tide. This works anywhere with a suitable beach — no wharf needed. It was the standard method for Thames barges and many coastal traders historically.³⁰

Lighters and tenders: Where a harbour is too shallow for the trading vessel to come alongside, cargo is transferred to a small boat (lighter) and ferried to shore. Labour-intensive but proven.

5.3 Port infrastructure priorities

Invest limited resources in the ports where coastal shipping is most needed:

1. Greymouth and Westport — the West Coast’s lifeline. Bar entrance improvements (channel markers, tide gauge communication) and wharf maintenance are high priorities
2. Gisborne — East Cape’s main port, the most isolated Tier 2 port by road
3. Picton — the Cook Strait terminal
4. Island services — wharf maintenance at Halfmoon Bay (Stewart Island), Tryphena (Great Barrier), and Waitangi (Chatham Islands)

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6. CREW REQUIREMENTS AND TRAINING

6.1 Numbers

A functioning coastal trading network with 20–40 active vessels requires approximately 80–200 crew (at 3–5 crew per vessel, with rotation allowing rest between voyages). Additional shore-side personnel — port coordinators, cargo handlers, maintenance workers — add perhaps 50–100 people.³¹

Total maritime workforce for the coastal network: approximately 130–300 people.

NZ’s existing maritime workforce includes approximately 1,500–2,000 commercial fishers, several hundred merchant mariners, Navy personnel, and thousands of experienced recreational sailors.³² The crew requirement is achievable from this base, though it competes with fishing for the same skilled people.

6.2 Required skills

Navigation: Coastal pilotage, chart reading, tide and current awareness, celestial navigation as GPS degrades (Doc #139). NZ coastal pilots (Doc #13) provide essential harbour-specific knowledge.

Seamanship: Sail handling (increasingly important as fuel depletes), anchoring, mooring, heavy weather management, towing. Vessel maintenance — a coastal trading crew must be able to make basic repairs at sea.

Cargo handling: Loading and lashing cargo for sea, operating derricks and winches, weight distribution to maintain vessel stability. Poorly loaded cargo is a safety risk — a shifted load can capsize a vessel.

Communication: HF radio operation, weather interpretation, schedule coordination.

First aid and survival: Maritime first aid, life-raft procedures, man-overboard recovery. Remote from shore-based medical care, crew must handle medical emergencies.

6.3 Training pathway

• Experienced fishers and merchant mariners transition to cargo service with minimal additional training — cargo handling and commercial operating procedures
• Experienced yachtsmen require training in commercial operations, cargo handling, heavier vessel handling, and crew management
• New entrants require 6–12 months of supervised sailing before independent watch-keeping, plus cargo handling training

NZ’s existing maritime training institutions (NZ Maritime School in Auckland, industry training organizations) can provide structured training if they remain operational. Apprenticeship aboard working vessels — the traditional method — is the practical fallback.³³

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7. WEATHER ROUTING AND SAFETY

7.1 NZ’s coastal weather patterns

NZ’s weather is dominated by the passage of frontal systems from the Tasman Sea, moving generally west to east. Key patterns for coastal shipping:³⁴

• Prevailing westerlies — particularly strong in the South Island and Cook Strait. Favourable for northward passages along the west coast; headwinds for southward passages
• Northeast/east winds in summer — particularly in the North Island. Associated with settled weather
• Southerly changes — cold fronts bringing strong S–SW winds, sometimes gale force. These can develop rapidly and are the primary hazard for coastal shipping
• Tropical cyclone remnants (summer/autumn) — occasional, bringing heavy rain and strong winds from the NE or N

7.2 Seasonal routing

Summer (November–March): Longer daylight, more settled weather, higher frequency of NE winds in the North Island. Preferred season for longer passages and West Coast operations.

Winter (May–August): Shorter daylight, more frequent and stronger frontal systems, colder conditions. Coastal operations continue but with reduced frequency and larger weather margins. West Coast operations may pause for extended periods.

Transitional seasons (April, September–October): Highly variable. Some of NZ’s worst storms occur in transitional periods.

7.3 Weather information

• HF radio weather broadcasts — MetService operates marine weather broadcasts that can continue as long as the agency and broadcast infrastructure function. This is a baseline-scenario assumption.³⁵
• Barometric pressure monitoring — every vessel carries a barometer. Rapid pressure drops indicate approaching fronts
• Local knowledge — experienced coastal operators learn the weather signs for their routes. This knowledge should be documented and shared
• Visual observation — cloud patterns, wind shifts, swell changes all provide warning. Traditional Polynesian weather reading is relevant here

7.4 Safety infrastructure

• HF radio for communication and distress (Doc #128) — every vessel
• Coastal lookouts and reporting — communities along the coast can report vessel movements and weather conditions, forming an informal vessel traffic service
• Search and rescue — NZ Coastguard and Navy SAR capability should be maintained. Under sail, SAR response times will be longer — self-rescue capability (life rafts, survival equipment) becomes more important
• Harbour refuges — passage planning should identify sheltered anchorages at regular intervals along each route where vessels can shelter from deteriorating weather

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8. INTEGRATION WITH ROAD AND RAIL

8.1 The last-mile problem

Coastal shipping delivers goods to ports. Most end users are inland. Connecting ports to inland consumers requires road or rail transport — the same systems under pressure from fuel and tire depletion.

8.2 Solutions

Prioritize rail connections: Ports with rail connections (Auckland, Tauranga, Wellington, Lyttelton, Port Chalmers, Napier) can distribute inland by electrified or wood-gas rail. Investing in port-to-rail connections increases the reach of coastal shipping.³⁶

Short-range road distribution: Even with fuel rationing, short-distance road transport (port to nearby towns) consumes far less fuel than long-haul trucking. Regional distribution hubs at ports — where coastal cargo is consolidated and distributed locally — extend the network efficiently.

River and harbour transport: Where rivers are navigable (Waikato, Whanganui historically), small barges can carry cargo further inland. The Whanganui River was a major transport route until the 1930s.³⁷ Feasibility of reactivating river transport depends on current channel conditions and vessel availability.

Animal-drawn transport: For the final link from port or railhead to farm or community, horse or ox-drawn carts on existing roads require no fuel. This is a Phase 3–4 development as draft animals are bred and trained (Doc #74).

Bicycle freight: Cargo bicycles and bicycle trailers can move 50–200 kg per trip over short distances (typically under 10–20 km on flat to moderate terrain).³⁸ For lightweight, high-value cargo distribution from port to town, this is effective (Doc #59).

8.3 Regional distribution hubs

Each major port should function as a regional distribution hub — a warehouse and consolidation point where coastal cargo is sorted and redistributed to inland destinations. This requires:

• Covered storage at the port
• Inventory management (ledger-based if electronic systems fail)
• Coordination with inland transport (whatever mode is available)
• A port agent or coordinator responsible for matching incoming cargo to distribution

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CRITICAL UNCERTAINTIES

Uncertainty	Impact	Mitigation
Condition of existing vessel fleet	Determines initial cargo capacity	Census and survey (Doc #8); prioritize maintenance of best vessels
Fuel availability for powered coastal vessels	Determines transition timeline from power to sail	Fuel allocation (Doc #53); begin sail training early
Condition of secondary port infrastructure	Some wharves may be unsafe; bar harbours may have silted	Physical survey required; budget for repairs
Weather under nuclear winter [contingency — outside baseline scenario]	Potentially stronger or shifted storm patterns; reduced visibility from atmospheric particulate. The baseline scenario assumes normal NZ weather patterns continue. If significant atmospheric loading occurs, storm frequency and intensity may increase; this is a contingency, not the expected outcome.	Conservative scheduling; larger weather margins; enhanced communication
Fishing fleet availability	Competition between fishing and cargo roles for same vessels	Seasonal allocation; purpose-built cargo vessels reduce pressure
Crew availability	Skilled mariners are in demand for fishing, Navy, and trade	Training pipeline; competitive conditions of service
Cook Strait crossing under sail	Currently handled by large powered ferries; transition to sailing vessels reduces capacity by an order of magnitude	Build purpose-designed Cook Strait sailing vessels; accept lower throughput; prioritize high-value cargo
Nuclear winter sea state [contingency — outside baseline scenario]	Southern Ocean storm patterns may intensify or shift, affecting the South Island coast and Cook Strait. This is a contingency; the baseline scenario does not assume changed storm patterns.	Insufficient data to predict; plan conservatively

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CROSS-REFERENCES

Document	Relationship
Doc #156 — Skills Census	Vessel and port inventory; maritime skills identification
Doc #13 — NZ Coastal Pilot and Harbour Guide	Essential navigation reference for every coastal route and harbour
Doc #33 — Tires	Road transport depletion drives demand for coastal alternatives
Doc #53 — Fuel Allocation	Fuel availability determines powered vessel operating life
Doc #78 — Food Preservation	Cargo includes preserved food; preservation enables longer supply chains
Doc #89 — NZ Steel Glenbrook	Major cargo source — steel products from Auckland distributed by sea
Doc #97 — Cement and Concrete	Cement from Golden Bay distributed coastally
Doc #100 — Harakeke Fiber	Rope and cordage for rigging and cargo handling
Doc #128 — HF Radio	Communication backbone for the coastal network
Doc #138 — Sailing Vessel Design	Design of new-build coastal trading vessels
Doc #139 — Celestial Navigation	Navigation as GPS degrades
Doc #141 — Boatbuilding Techniques	Construction of new coastal trading vessels
Doc #142 — Trans-Tasman and Pacific Trade Routes	International extension of the coastal network
Doc #145 — Workforce Reallocation	Maritime crew as part of national workforce planning
Doc #151 — NZ–Australia Relations	Coastal network feeds into international trade system
Doc #160 — Heritage Skills Preservation	Traditional boatbuilding and seamanship knowledge

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FOOTNOTES

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1. NZ’s coastline length is variously reported between 9,000 and 18,000 km depending on resolution of measurement and inclusion of islands. Land Information New Zealand (LINZ) and Stats NZ provide official figures. The “over 15,000 km” figure includes main islands and significant offshore islands. NZ has approximately 13 major commercial ports, with additional regional and recreational harbours. Maritime New Zealand maintains the port and harbour register.↩︎

2. NZ’s coastal shipping history is documented in McLean, G., “The Southern Octopus: The Rise of a Shipping Empire in NZ 1882–1913,” NZ Ship and Marine Society, 1990. Before rail and road development, coastal shipping was NZ’s primary freight and passenger transport system. The Union Steam Ship Company operated an extensive coastal service from the 1870s to the 1960s.↩︎

3. NZ domestic freight data from Ministry of Transport, National Freight Demands Study (most recent edition). Road freight dominates NZ domestic transport. The exact current-year figure varies with economic conditions, but 90%+ by road is consistent across recent studies. https://www.transport.govt.nz/↩︎

4. NZ’s rail network (approximately 4,000 km, operated by KiwiRail) serves main trunk routes in both islands but has significant gaps in coverage. The West Coast South Island, Northland north of Whāngārei, East Cape, and Coromandel are not served by rail. Electrification is limited to the North Island Main Trunk between Hamilton and Palmerston North, though some suburban lines in Auckland and Wellington are also electrified. KiwiRail network maps: https://www.kiwirail.co.nz/↩︎

5. Fuel efficiency of coastal shipping versus road transport: International Maritime Organization (IMO) emissions data and NZ Transport Agency comparisons. Small coastal vessels are less efficient per tonne-km than large container ships but still more efficient than road transport for medium- to long-distance freight. Actual figures vary widely with vessel type, loading, speed, and conditions. The 5–15 g/tonne-km estimate for small coastal vessels is approximate and based on general maritime fuel consumption data; NZ-specific verification is needed.↩︎

6. West Coast (Te Tai Poutini) region population from Stats NZ census data. The region has approximately 32,000 residents distributed across Westport, Greymouth, Hokitika, and smaller communities. Road access via Arthur’s Pass (SH73), Lewis Pass (SH7), and Haast Pass (SH6) is vulnerable to landslips, flooding, and snow. All three routes have experienced multi-day closures in recent years. West Coast Regional Council and NZTA maintenance data.↩︎

7. NZ port listing and capabilities from Maritime NZ and individual port company websites. Ports of Auckland: https://www.poal.co.nz/; Port of Tauranga: https://www.port-tauranga.co.nz/; CentrePort (Wellington): https://www.centreport.co.nz/; Lyttelton Port Company: https://www.lpc.co.nz/; Port Otago: https://www.portotago.co.nz/; etc.↩︎

8. Greymouth and Westport bar harbour conditions are documented in LINZ hydrographic charts and NZ Coastal Pilot publications. Both bars are dangerous in heavy westerly or NW swell and have claimed numerous vessels historically. The Greymouth bar has a tidal range of approximately 2.5 metres and a controlling depth that varies with sand movement. Vessels drawing more than approximately 4 metres should not attempt the bar. Conditions change with swell, tide, river flow, and recent weather.↩︎

9. NZ fishing fleet data from Fisheries New Zealand and Maritime NZ vessel registration records. The number of registered commercial fishing vessels has declined from over 1,700 in the early 2000s to approximately 1,200 as of recent reporting, reflecting fleet consolidation. NZ’s recreational boat fleet is estimated at over 500,000 vessels of all types, the vast majority being small trailer boats. https://www.mpi.govt.nz/fishing-aquaculture/↩︎

10. Offshore-capable yacht estimates are based on NZ yacht club memberships, marina berth numbers, and industry assessments. NZ has a strong offshore sailing tradition, with approximately 1,500–2,500 keelboats of 9 metres or larger in main centres (Auckland, Wellington, Christchurch, Tauranga, Nelson). The number capable of sustained offshore work (seaworthy, self-righting, with adequate ground tackle and sail wardrobe) is a subset of this. Figure requires verification through the census (Doc #8).↩︎

11. Cook Strait ferry fuel consumption estimates based on Interislander and Bluebridge vessel specifications and general marine fuel consumption data for RoPax ferries of similar displacement (5,000–12,000 tonnes). The current Interislander vessels (Kaitaki, Aratere) consume approximately 8–15 tonnes of marine diesel per crossing; smaller Bluebridge vessels (Connemara, Straitsman) consume approximately 5–10 tonnes. Actual consumption varies with sea state, loading, and speed. KiwiRail annual reports provide aggregate fuel consumption data. Figures require verification from vessel operators.↩︎

12. Cook Strait distance and conditions: LINZ charts NZ 463 and NZ 4633. The narrowest point is approximately 22 km (Perano Head to Cape Terawhiti), but the navigable shipping channel through Tory Channel to Picton is approximately 92 km from Wellington. Tidal streams in the strait reach 4–5 knots in the narrows. Cook Strait has been sailed by vessels of all sizes since Polynesian arrival; it is demanding but navigable under sail with appropriate weather windows and tidal timing.↩︎

13. Māori maritime traditions: Howe, K.R. (ed), “Vaka Moana: Voyages of the Ancestors,” Auckland War Memorial Museum, 2006. Polynesian navigation and wayfinding methods are well-documented in ethnographic and historical literature. Modern waka hourua programmes (including Te Aurere and Haunui) maintain and teach traditional navigation. Evans, J., “The Discovery of Aotearoa,” Reed Publishing, 1998, provides context on traditional Pacific voyaging to NZ.↩︎

14. NZ boatyard and marine services estimates based on NZ Marine Industry Association membership data and Maritime NZ records. NZ has a concentrated boatbuilding industry, particularly in Auckland, Tauranga, Nelson, and Whanganui. Stainless steel fastener stocks are finite — NZ does not manufacture stainless steel fasteners domestically. Epoxy and polyester resin are imported petrochemical products with finite NZ stocks. Domestically produced polyester resin would require bio-derived glycols and phthalic anhydride — a multi-step chemical synthesis requiring infrastructure not currently present in NZ; this is a Phase 4+ possibility, not a near-term substitute. Boatyard count and resin stock figures require verification through the national asset census (Doc #8).↩︎

15. Thames sailing barges: Carr, F.G.G., “Sailing Barges,” Peter Davies, 1951; March, E.J., “Spritsail Barges of Thames and Medway,” Percival Marshall, 1948. Thames barges typically carried 80–150 tonnes (larger examples to 220 tonnes); crewed by skipper and mate, occasionally with a third hand for longer passages. The estuary and east coast environment — tide-dominated, moderate swell, enclosed waters — is fundamentally different from the open-ocean exposures on NZ’s West Coast and the turbulent tidal environment of Cook Strait. The design concept (shallow draft, flat bottom, large hold, small crew) is transferable; the specific scantlings and freeboard are not. Doc #138 addresses NZ-adapted design in detail.↩︎

16. Route distances are approximate and derived from LINZ chart measurements and coastal passage planning references. Actual distances vary with routing (direct vs. inshore), stops, and weather diversions. Passage times under power assume economical cruising speed of 7–10 knots for fishing-vessel-type craft; under sail assume average speed of 4–6 knots with realistic wind allowance. All passage times are indicative only and will vary with vessel, crew, loading, and conditions. Verify against current LINZ charts NZ 40 (North Island), NZ 60 (Cook Strait), and NZ 80 (South Island) coastal series.↩︎

17. Route distances are approximate and derived from LINZ chart measurements and coastal passage planning references. Actual distances vary with routing (direct vs. inshore), stops, and weather diversions. Passage times under power assume economical cruising speed of 7–10 knots for fishing-vessel-type craft; under sail assume average speed of 4–6 knots with realistic wind allowance. All passage times are indicative only and will vary with vessel, crew, loading, and conditions. Verify against current LINZ charts NZ 40 (North Island), NZ 60 (Cook Strait), and NZ 80 (South Island) coastal series.↩︎

18. NZ coastal weather patterns: MetService and NIWA publications on NZ climate and marine weather. “New Zealand Weather and Climate” (NIWA publication) provides regional weather pattern summaries. NZ Maritime Safety Authority weather guidance for coastal navigation. The East Cape coast is noted for its exposure and limited shelter options between Ōpōtiki and Gisborne — approximately 200 km of open coastline with few harbours of refuge.↩︎

19. Cook Strait weather and tidal conditions: NZ Nautical Almanac; LINZ tidal stream atlases; MetService Cook Strait marine forecast. The strait acts as a funnel between the North and South Islands, accelerating winds and concentrating tidal flow. Conditions can change rapidly — a moderate crossing can become dangerous within an hour if a southerly change arrives.↩︎

20. Route distances are approximate and derived from LINZ chart measurements and coastal passage planning references. Actual distances vary with routing (direct vs. inshore), stops, and weather diversions. Passage times under power assume economical cruising speed of 7–10 knots for fishing-vessel-type craft; under sail assume average speed of 4–6 knots with realistic wind allowance. All passage times are indicative only and will vary with vessel, crew, loading, and conditions. Verify against current LINZ charts NZ 40 (North Island), NZ 60 (Cook Strait), and NZ 80 (South Island) coastal series.↩︎

21. Greymouth and Westport bar harbour conditions are documented in LINZ hydrographic charts and NZ Coastal Pilot publications. Both bars are dangerous in heavy westerly or NW swell and have claimed numerous vessels historically. The Greymouth bar has a tidal range of approximately 2.5 metres and a controlling depth that varies with sand movement. Vessels drawing more than approximately 4 metres should not attempt the bar. Conditions change with swell, tide, river flow, and recent weather.↩︎

22. Route distances are approximate and derived from LINZ chart measurements and coastal passage planning references. Actual distances vary with routing (direct vs. inshore), stops, and weather diversions. Passage times under power assume economical cruising speed of 7–10 knots for fishing-vessel-type craft; under sail assume average speed of 4–6 knots with realistic wind allowance. All passage times are indicative only and will vary with vessel, crew, loading, and conditions. Verify against current LINZ charts NZ 40 (North Island), NZ 60 (Cook Strait), and NZ 80 (South Island) coastal series.↩︎

23. Foveaux Strait conditions from LINZ charts and NZ Coastal Pilot. Tidal streams reach 3–4 knots in the main channel. The strait is approximately 35 km wide at its narrowest. Combined with Southern Ocean swell and the proximity of the Sub-Antarctic weather systems, Foveaux Strait is a demanding passage for small vessels in winter.↩︎

24. Route distances are approximate and derived from LINZ chart measurements and coastal passage planning references. Actual distances vary with routing (direct vs. inshore), stops, and weather diversions. Passage times under power assume economical cruising speed of 7–10 knots for fishing-vessel-type craft; under sail assume average speed of 4–6 knots with realistic wind allowance. All passage times are indicative only and will vary with vessel, crew, loading, and conditions. Verify against current LINZ charts NZ 40 (North Island), NZ 60 (Cook Strait), and NZ 80 (South Island) coastal series.↩︎

25. Island community populations from Stats NZ 2023 Census data. Stewart Island / Rakiura (Halfmoon Bay): usually-resident population approximately 381 (2023 Census); seasonal variation significant with tourism workers and fishing crew. Great Barrier Island / Aotea: usually-resident population approximately 900 (2023 Census); summer population substantially higher. Chatham Islands / Rēkohu: usually-resident population approximately 600 (2023 Census). All figures subject to revision; verify against most recent Stats NZ release at https://www.stats.govt.nz/↩︎

26. Island community populations from Stats NZ 2023 Census data. Stewart Island / Rakiura (Halfmoon Bay): usually-resident population approximately 381 (2023 Census); seasonal variation significant with tourism workers and fishing crew. Great Barrier Island / Aotea: usually-resident population approximately 900 (2023 Census); summer population substantially higher. Chatham Islands / Rēkohu: usually-resident population approximately 600 (2023 Census). All figures subject to revision; verify against most recent Stats NZ release at https://www.stats.govt.nz/↩︎

27. Island community populations from Stats NZ 2023 Census data. Stewart Island / Rakiura (Halfmoon Bay): usually-resident population approximately 381 (2023 Census); seasonal variation significant with tourism workers and fishing crew. Great Barrier Island / Aotea: usually-resident population approximately 900 (2023 Census); summer population substantially higher. Chatham Islands / Rēkohu: usually-resident population approximately 600 (2023 Census). All figures subject to revision; verify against most recent Stats NZ release at https://www.stats.govt.nz/↩︎

28. Harakeke fibre rope performance compared to synthetic rope: harakeke (Phormium tenax) cordage has lower tensile strength than nylon or polyester of equivalent diameter — approximately 40–60% of nylon’s breaking strength when new, and more susceptible to degradation from UV exposure and moisture. See Doc #100 (Harakeke Fiber) for detailed specifications. Steel hardware (shackles, blocks) can be fabricated from NZ Steel Glenbrook output (Doc #89); purpose-built marine hardware requires machining capacity.↩︎

29. Manual cargo handling rates based on historical stevedoring data and general materials handling literature. Pre-containerization stevedoring crews of 6–12 workers typically handled 1–5 tonnes per hour of mixed breakbulk cargo. The wide range reflects differences in cargo type (bagged goods faster than irregular shapes), stacking distance, and worker experience. Mechanized handling rates from port industry data. See: Couper, A.D., “The Geography of Sea Transport,” Hutchinson, 1972.↩︎

30. Beaching and drying out as a cargo handling method is well-documented in Thames barge and traditional coastal shipping history. See: Carr, F.G.G., “Sailing Barges,” Peter Davies, 1951. The method requires a suitable beach (firm sand or gravel, appropriate tidal range), a flat-bottomed vessel, and knowledge of local tidal conditions. NZ has numerous beaches suitable for this practice.↩︎

31. Crew and shore-side personnel estimates are based on the assumption of 20–40 active vessels averaging 3–5 crew each, operating on a rotation that allows rest between voyages (typically 1:1 or 2:1 sea-to-shore ratio). Shore-side estimates include port coordinators, cargo handlers, maintenance workers, and administrative staff. These figures are estimates; actual requirements depend on service frequency, vessel size, and operational patterns. Verification through operational experience would refine these numbers.↩︎

32. NZ fishing fleet data from Fisheries New Zealand and Maritime NZ vessel registration records. The number of registered commercial fishing vessels has declined from over 1,700 in the early 2000s to approximately 1,200 as of recent reporting, reflecting fleet consolidation. NZ’s recreational boat fleet is estimated at over 500,000 vessels of all types, the vast majority being small trailer boats. https://www.mpi.govt.nz/fishing-aquaculture/↩︎

33. NZ maritime training: The NZ Maritime School (Te Kura Moana, part of Te Pūkenga/UNITEC) in Auckland is NZ’s primary maritime training institution, offering certificates for deck officers, marine engineers, and other maritime qualifications. Maritime NZ sets qualification standards. Historically, most merchant mariners trained through sea-time apprenticeships supplemented by shore-based courses — this model would likely be reinstated under recovery conditions. https://www.maritimenz.govt.nz/↩︎

34. NZ coastal weather patterns: MetService and NIWA publications on NZ climate and marine weather. “New Zealand Weather and Climate” (NIWA publication) provides regional weather pattern summaries. NZ Maritime Safety Authority weather guidance for coastal navigation. The East Cape coast is noted for its exposure and limited shelter options between Ōpōtiki and Gisborne — approximately 200 km of open coastline with few harbours of refuge.↩︎

35. MetService marine weather services: MetService is NZ’s official weather forecasting agency and produces marine weather forecasts and warnings for NZ coastal waters, Cook Strait, and the wider NZ maritime area. These are broadcast on marine VHF and HF radio frequencies. Continued operation depends on grid power (baseline assumption — see style guide) and maintenance of forecasting capability, which relies on computational infrastructure and trained meteorologists. https://www.metservice.com/marine/↩︎

36. NZ’s rail network (approximately 4,000 km, operated by KiwiRail) serves main trunk routes in both islands but has significant gaps in coverage. The West Coast South Island, Northland north of Whāngārei, East Cape, and Coromandel are not served by rail. Electrification is limited to the North Island Main Trunk between Hamilton and Palmerston North, though some suburban lines in Auckland and Wellington are also electrified. KiwiRail network maps: https://www.kiwirail.co.nz/↩︎

37. Whanganui River navigation history: the Whanganui River was navigable by steamship for approximately 200 km inland from the river mouth and served as a major transport route for the central North Island from the 1860s to the 1930s, when road development reduced demand. The river’s navigability today for even small vessels would need to be assessed — river conditions change with sedimentation, flood damage, and riparian vegetation growth. Whanganui Regional Museum and Department of Conservation historical records provide documentation.↩︎

38. Cargo bicycle and trailer capacity based on commercial cargo bicycle specifications and bicycle logistics studies. Standard cargo bikes carry 50–100 kg; purpose-built cargo trikes and bicycle trailers extend this to 150–250 kg on flat terrain, with capacity declining on grades exceeding 3–5%. Range and capacity figures assume flat to moderate terrain and maintained road surfaces. See Doc #59 (Bicycle Fleet) for NZ-specific bicycle infrastructure planning.↩︎