What is the difference between sea freight and air freight?
Sea freight moves goods in containers on ships and takes weeks. Air freight moves them on aircraft and takes days. Sea wins on cost for anything heavy or bulky, and air wins on speed. The table below sets the two side by side.
| Factor | Sea freight | Air freight |
|---|---|---|
| Speed | Slow. Roughly two to three weeks to China and six to eight weeks to Europe. | Fast. Typically one to two days to anywhere in the world. |
| Cost per kilogram | Very low, because a ship spreads the voyage across thousands of tonnes. | Typically five to ten times the cost of sea. |
| Best for | Heavy, bulky and non-urgent goods, such as machinery, furniture and bulk commodities. | Urgent, perishable and high-value goods, such as medical supplies, fresh seafood and electronics. |
| How it is priced | By container (FCL) or by cubic metre or tonne (LCL). | By chargeable weight, the higher of actual and volumetric weight. |
| Key document | Bill of Lading, which is a document of title. | Air Waybill, which is not a document of title. |
| Share of NZ trade | Around 99.7% by volume. | Around 19% by value. |
Heavy, bulky or non-urgent goods go by sea. Urgent, perishable or high-value goods justify air. Where the shipment sits between the two, the forwarder works it out from the deadline and the budget.
Why does sea freight carry most of New Zealand's trade?
New Zealand is an island nation a long way from its trading partners, and around 99.7% of our trade by volume travels by sea. A single container ship can carry thousands of tonnes, so the cost of the voyage is spread across all that cargo and the price per kilogram is low. That is why logs, dairy powder and machinery nearly always go by ship.
The trade-off is time. Allow roughly two to three weeks from China and six to eight weeks from Europe, plus loading, port handling and customs clearance either side of the voyage. The busiest container ports are the Port of Tauranga, Ports of Auckland, Lyttelton near Christchurch, and Napier. Part of a forwarder's job is choosing the port that suits the sailing schedule and where the importer's goods need to end up.
What is the difference between FCL and LCL?
FCL means full container load: one customer's goods fill the whole container, usually a 20-foot or 40-foot steel box. LCL means less than container load: several customers share one container and the forwarder consolidates their goods. Consolidation is one of the most valuable things a forwarder does, because it lets a small importer pay for a share of a container instead of the whole thing.
LCL suits a few pallets. FCL suits a load big enough to fill the container, and it is simpler because the container is packed and sealed once and stays sealed until it reaches the consignee.
When is air freight worth the extra cost?
Air freight is worth it when speed pays for itself. That means urgent shipments needed in days, perishable goods such as fresh seafood or flowers, and high-value items such as electronics, where a fast and secure trip is worth the price. Air carries only a small slice of New Zealand's trade by volume, but because it moves high-value goods it accounts for around 19% of our trade by value.
For a forwarder, air cargo means tight timelines and careful pricing. A flight can put New Zealand crayfish on a plate in Asia the next day, which no ship can match.
What is chargeable weight in air freight?
Chargeable weight is the figure an airline bills on, and it is the higher of the actual weight and the volumetric weight. A plane runs out of space before it runs out of weight, so light but bulky cargo is charged for the space it takes. The air freight standard is 1 cubic metre equals 167 kg.
A carton that weighs 100 kg on the scales but fills one cubic metre is charged as 167 kg, because 167 is the higher figure. Importers often miss this when they compare a quote with the weight on their packing list. Sea freight has no equivalent trap for a full container, but LCL is priced on weight or volume, whichever the carrier rates higher.
How do you choose between sea and air?
A forwarder weighs four factors and matches the mode to the need:
- Urgency. How soon does it need to arrive? A tight deadline pushes towards air.
- Size and weight. Large or heavy loads are far cheaper by sea.
- Value. High-value goods can justify the speed and security of air.
- Budget. What is the client willing to spend to hit the deadline?
Two examples from the Capability Solutions course show how this works. A Waikato manufacturer with ten pallets, about eight tonnes, going to Shanghai within four to five weeks should go by sea in a full container, trucked to the Port of Tauranga. Eight tonnes fills a 20-foot container, sea is far cheaper for that volume, and a two to four week transit sits inside the deadline. A Christchurch supplier with 50 kg of medical supplies that must reach a Sydney hospital within four days has to fly. Any route that ends in a ship misses the deadline, and 50 kg keeps the absolute cost manageable.
Which documents differ between sea and air?
The central sea document is the Bill of Lading, issued by the shipping line. It does three jobs at once: it is a contract of carriage, a receipt that the goods were loaded, and a document of title, so whoever holds the original can claim the goods. Because of that third job, a wrong name or cargo description on a Bill of Lading can cause serious delays.
The air equivalent is the Air Waybill. It is a contract of carriage and a receipt, but it is not a document of title, so the goods go straight to the named consignee. It can be issued by the airline (a Master AWB) or by a forwarder (a House AWB), and it is usually electronic now. For the full document set, see what a freight forwarder actually does.
Do biosecurity and customs rules change with the mode?
The legal framework is the same for both. The Biosecurity Act 1993 and MPI's import health standards apply whichever way the goods arrive, and the importer or their agent lodges the customs entry through the Trade Single Window. The practical risk differs. Sea containers and wooden pallets and crating can carry pests, so a container may be directed to a transitional facility where an Accredited Person supervises unpacking. Wooden packaging needs to meet the ISPM-15 treatment standard on either mode.
Check the goods against the relevant import health standard before booking. A missing certificate found at the border holds the whole consignment and storage costs run while it is sorted out.
The Incoterms rule in your sale contract decides who books and pays for the main carriage, whether sea or air. Agree it before anyone books. See Incoterms 2020 explained for New Zealand importers and exporters. To see where a mode decision fits in the whole chain, read the journey of an import to New Zealand, and for who books it, freight forwarder vs customs broker vs 3PL.
Sea freight carries almost all of New Zealand's trade because it is cheap for large volumes, and the price is time. Air freight is fast and costs far more, so it suits urgent, perishable or high-value goods. Choose by urgency, size and weight, value and budget, and remember that air is billed on chargeable weight, not just what the cargo weighs on the scales.
A short glossary
- FCL. Full container load. One customer's goods fill the whole container.
- LCL. Less than container load. Several customers share one container.
- Consolidation. Combining small shipments from different customers into one container or one airline booking.
- Bill of Lading. The sea freight document issued by the shipping line. A contract, a receipt and a document of title.
- Air Waybill (AWB). The air freight document. A contract and a receipt, but not a document of title.
- Volumetric weight. Cargo volume converted to a weight, at 167 kg per cubic metre for air freight.
- Chargeable weight. The higher of actual and volumetric weight. It is what the airline bills on.
- Consignee. The party named to receive the goods.
Want to work in freight forwarding?
Choosing the right mode is the skill clients pay a forwarder for. Start with the free Capability Solutions courses, or see how to get into New Zealand freight and logistics.
Start Your Career Free CoursesWhere to learn this properly
Capability Solutions runs free online training for people starting out in New Zealand freight, logistics and biosecurity. A full Introduction to Freight Forwarding course covering modes, cargo, documents, borders and risk is coming soon. To be told when it opens, email Gordon@findlayandco.co.nz and we will put you on the list.
If you are working out where you fit, how to start a career in freight forwarding in New Zealand covers the entry points.
Frequently asked questions
Is sea freight or air freight cheaper for importing into New Zealand?
Sea freight is cheaper for almost every shipment of any size. Air freight typically costs five to ten times as much per kilogram as sea. A container ship spreads the cost of a voyage across thousands of tonnes of cargo, which is why the price per kilogram is so low.
How long does sea freight take to New Zealand?
Transit times depend on the origin. As a guide, ocean transit is roughly two to three weeks to or from China and six to eight weeks to or from Europe. Sea freight to or from Australia takes well over a week. Allow extra time for loading, port handling and customs clearance on top of the voyage.
What is chargeable weight in air freight?
Chargeable weight is the figure an airline bills on. It is the higher of the actual weight and the volumetric weight. Volumetric weight converts the space the cargo takes up into a weight, using the air freight standard of 1 cubic metre equals 167 kg. A light but bulky carton that weighs 100 kg and fills one cubic metre is charged as 167 kg.
What is the difference between FCL and LCL?
FCL means full container load: one customer's goods fill the whole container. LCL means less than container load: several customers share one container and the forwarder consolidates their goods. LCL suits shipments too small to fill a container, and FCL is usually better value once a load is big enough to fill one.
What is the difference between a Bill of Lading and an Air Waybill?
A Bill of Lading is issued by the shipping line for sea freight. It is a contract of carriage, a receipt for the goods and a document of title, so whoever holds the original can claim the goods. An Air Waybill is the air freight equivalent. It is a contract of carriage and a receipt, but it is not a document of title, and the goods go straight to the named consignee.
When is air freight worth the extra cost?
Air freight is worth it when speed pays for itself: urgent shipments needed in days, perishable goods such as fresh seafood or flowers, and high-value items such as electronics where a fast and secure trip justifies the price. Air carries only a small share of New Zealand trade by volume but around 19 percent by value.
How much of New Zealand's trade goes by sea?
Around 99.7 percent of New Zealand's trade by volume travels by sea. New Zealand is an island nation a long way from its trading partners, so for anything heavy, bulky or not urgent the ocean is almost always the answer.
Do biosecurity rules differ between sea and air freight?
The same Biosecurity Act 1993 and MPI import health standards apply to both. What changes is the practical risk: sea containers and wooden pallets and crating can carry pests, so goods may be directed to a transitional facility where an Accredited Person supervises unpacking. Checking the goods against the import health standard before booking is part of choosing any mode.