An island's supply chain has a single characteristic that determines almost everything else: there is no road in. Every physical good arrives by ship or aircraft, and the properties of that link propagate into prices, stock depth and vulnerability.
| Freight | almost entirely sea, by volume |
|---|---|
| Air | passengers, mail, urgent and perishable cargo |
| Structural feature | transhipment through regional hubs |
| Consequence | high per-unit cost, limited stock depth |
Sea freight
- Container services on scheduled rotations
- Transhipment through larger regional ports for most long-haul cargo
- Bulk cargo for fuel and construction materials
- Inter-island services to the dependencies
- Cruise calls, which are passenger rather than freight traffic
The transhipment point explains a great deal. Goods from a distant origin typically travel on a large vessel to a regional hub, then on a smaller feeder vessel to the island — which adds handling, time and cost at the transfer.
It also adds a dependency: disruption at the hub affects the island even when nothing local has gone wrong, which is why regional port congestion shows up in local availability.
Why freight cost per unit is high
- Small volumes mean less negotiating leverage and fewer full containers
- Feeder legs cost more per unit than main-line legs
- Imbalanced trade means containers often return empty, and that cost is priced in
- Handling at smaller ports is less mechanised
- Insurance and demurrage add further layers
The third is worth understanding because it is not obvious. A route that carries full containers inbound and empty ones outbound must recover the round-trip cost from the inbound leg alone, which raises the price of everything imported.
This is a structural feature of import-dependent economies, and it is one reason export development matters beyond its direct earnings.
Air links
- An international airport handling regional and long-haul services
- A smaller airport on the dependency serving inter-island flights
- Airlift capacity as a direct constraint on tourism volume
- Seasonal schedules varying with demand
- Air cargo for perishables, pharmaceuticals and urgent items
The third is the key economic point. Tourism arrivals are limited by available seats, not only by demand, so route decisions taken by airlines abroad directly determine a significant part of national economic activity.
This is a form of external dependence that does not appear in trade statistics but is as consequential as any of them.
Stock depth
The practical consequence for residents and businesses:
- Inventory is thin because holding stock on an island is expensive
- A missed sailing produces visible gaps on shelves
- Unusual items may need to be ordered specially
- Spare parts are a recurring difficulty for equipment
- Perishables depend on cold chain integrity through the whole journey
The fourth affects business planning materially. Equipment downtime on an island is measured in shipping time, not in repair time, which is why holding critical spares locally is standard practice despite the cost.
Resilience
- Storm closure of ports and airports interrupts supply
- Pre-season stocking is standard practice for essentials
- Fuel storage capacity determines how long the island runs without resupply
- Port damage is the critical vulnerability after a major event
- Regional cooperation supports post-disaster logistics
The fourth is the single point of failure that disaster planning concentrates on. Relief supplies arrive through the port, so damage to the port compounds every other consequence of an event — which is why port resilience investment ranks high in small island adaptation planning.
Frequently asked questions
Why does transhipment matter?
Most cargo transfers to a feeder vessel at a regional hub, adding cost and time — and making the island vulnerable to congestion elsewhere.
Why is freight so expensive per unit?
Partly because containers often return empty, so the round-trip cost is recovered from the inbound leg alone.
How does airlift affect the economy?
Tourism arrivals are limited by available seats, so route decisions made by airlines abroad determine a significant part of economic activity.
Why is port damage the critical vulnerability?
Because relief supplies arrive through it, so damage to the port compounds every other consequence of a disaster.
