What does air cargo insurance cover, and how is it different from ocean cargo insurance?

What is the same in both modes

The confusion is expensive because almost nobody looks at it. People assume "cargo insurance is cargo insurance" and that declaring the shipment is enough. In practice, an air shipment framed as a marine one leaves gaps that surface exactly when there is a claim.

• The insured risk: total or partial loss and physical damage to the goods in transit.
• The warehouse-to-warehouse logic: good cover starts when the cargo leaves the origin warehouse and ends at the destination warehouse, including the inland legs at both ends — which in air freight is where most incidents happen.
• The core exclusions: delay in itself, inherent vice of the goods, insufficient packing by the insured, willful misconduct of the insured and, in certain cases, carrier insolvency.
• The insurable interest requirement: the policy pays whoever bore the risk at the moment of the damage, regardless of transport mode.

What changes, and changes materially

1. The window at destination is half as long

Under standard market marine clauses, cover continues for up to 60 days after discharge from the vessel at the final port; under the standard air cargo clauses that period is half: 30 days from unloading from the aircraft at the final place of discharge. Each certificate may set different terms, so the exact period is confirmed when it is issued.

It reads like a technicality and it is the cause of avoidable declines. Air cargo sitting in a bonded warehouse waiting on a stuck clearance burns through that window fast. If release takes longer than the window set in the certificate, damage found afterwards can fall outside cover even though the certificate is in force.

2. General average does not exist in air

General average is an institution of maritime law: when the master sacrifices part of the cargo or incurs extraordinary expense to save the vessel and the rest of the shipment, every cargo owner contributes pro rata, damaged or not. In air there is no such thing — no declaration, no contribution.

The practical consequence: in marine, an uninsured shipment can end up with intact cargo held at destination until its owner posts security for the contribution. In air that risk does not exist — but the next point more than makes up for it.

3. The carrier's limit is calculated by weight, not by value

Under the Montreal Convention, an airline's liability for loss of or damage to cargo is limited by weight, unless a special declaration of value is made and surcharged. In marine, the Hague-Visby Rules limit per package or per kilo, whichever is higher.

This is where air freight leaves the most money on the table, and it is the easiest commercial argument to make: air cargo is typically the highest value per kilo there is. A five-kilo box of electronics or critical spare parts worth tens of thousands of dollars is compensated for its five kilos if carrier liability is the only protection in place. The gap between real value and what the airline pays is far wider than in marine.

4. War cover is "airborne", not "waterborne"

War cover has its own clause set for air cargo. In marine it operates waterborne — attaching on loading on board and ceasing on discharge; in air it operates airborne, anchored to the conveyance in the same way. In neither case does war cover reach the inland leg (strikes cover, by contrast, follows the warehouse-to-warehouse logic), and that is the distinction the intermediary has to be able to explain.

5. Postal sendings are usually outside

Standard market air cargo conditions usually exclude sendings by post. As general market practice, a courier shipment documented under an air waybill is treated as cargo and a postal consignment is not; in each case this is confirmed when the certificate is issued. It is a distinction clients almost never make, and one worth clearing up before rather than after.

The real air risks are not the marine ones

• Length of exposure — Ocean: Weeks; Air: Hours or days
• Typical damage — Ocean: Wetting, stowage, containers overboard, salt corrosion; Air: Terminal handling, drops, targeted theft, apron exposure
• Where risk concentrates — Ocean: During the voyage; Air: At origin and destination, on the ground
• Value per kilo — Ocean: Low to medium; Air: High to very high

The reading matters: in air, risk concentrates in the inland legs and the terminals, not in the flight. Which is why cover that starts at the origin airport and ends at the destination airport leaves out precisely where the damage happens. Warehouse-to-warehouse cover is not a luxury in air freight — it is the whole point.

Which air cargo to check before promising cover

A good share of what flies is high-value, easily resold cargo — consumer electronics, jewelry and precious metals, valuable documents or works of art — which insurers typically review case by case before accepting. Do not assume anything in advance. The terms for those shipments are confirmed when the shipment is declared and the certificate is issued — before anything is promised to the client.

What a freight forwarder or customs broker does with this

• 1. Frame every shipment by its actual mode, not by habit. An air shipment declared as marine is a problem waiting for a claim.
• 2. Flag the cover window at destination when cargo goes into a warehouse. It is a data point that prevents avoidable declines, and clients thank you for it.
• 3. Use the weight-based limit as an argument, not a threat: a client who understands that high-value cargo would be compensated by weight understands on their own why they need cover.
• 4. Check the commodity before quoting in the sensitive categories above.

At Proteus Cargo, cover operates warehouse to warehouse and on any route worldwide, across ocean and air, including the inland legs at both ends, with no deductibles as the general rule of the program — perishable and refrigerated cargo cover is the exception and does carry a deductible for ordinary claims — backed by world-class insurers and reinsurers in the markets of London, Germany and France. Through the Partner Program you offer that cover inside your own service, relying on a policy that is already underwritten and active: no capital, no insurance infrastructure, no technical expertise required. We operate in Chile, Peru, Mexico, Colombia, Argentina, Paraguay and Ecuador, and insure more than 12,000 shipments a year.

In one line

Air cargo insurance is not marine cover flown on a plane: it covers a shorter window at destination, knows nothing of general average, and faces a carrier limit that ignores the value of what it is carrying.

Want to review how the air freight in your book is covered? Book a 30-minute meeting, no strings attached.