Cargo Insight
Maritime & Sea Cargo
What Is Sea Cargo? A Complete Guide to Sea Freight.
Understand how goods move by sea, from exporters and shipping containers to ports, cargo ships, customs and final delivery.
What is sea cargo?
Sea cargo refers to goods transported from one location to another by ship. It is one of the most important forms of international freight transportation, connecting manufacturers, exporters, importers, businesses and consumers across the world.
Also commonly described as sea freight or ocean freight, maritime transportation can move everything from everyday containerised products to vehicles, machinery, refrigerated goods, bulk commodities and oversized equipment.
Unlike air freight, which prioritises speed, sea cargo is generally suited to larger volumes of goods and longer international distances. A modern cargo journey can involve several stages, including inland transport, port handling, customs procedures, containerisation, vessel transport and delivery at the destination.
For Australia, Papua New Guinea and the wider Pacific, maritime transport is particularly important because of the region's geography and extensive coastline.
How does sea cargo work?
A shipment does not simply move directly from one warehouse to another. It passes through a network of transport providers, ports, terminals, documentation and regulatory processes.
Preparing the Shipment
The exporter prepares the goods, packaging, documentation and transportation arrangements before the shipment begins.
Inland Transport
Cargo may travel by truck, rail or another form of inland transportation from the supplier or warehouse to the departure port.
Port and Terminal
At the port, cargo is processed through a terminal where containers and other freight are handled before being loaded onto a vessel.
Ocean Transport
The vessel carries the cargo between ports. Depending on the route, the shipment may travel directly or through one or more transhipment ports.
Destination Port
Once the vessel reaches its destination, cargo is unloaded and processed through the destination terminal and relevant customs procedures.
Final Delivery
After clearance and port handling, the goods can continue by road, rail or another transport method to the final destination.
What types of cargo are transported by sea?
Different goods require different methods of handling, packaging, storage and transportation.
Containerised Cargo
Container shipping is one of the most widely used methods for transporting manufactured goods, consumer products, machinery and many other forms of general freight.
Specialised Cargo
Sea transport can also accommodate refrigerated goods, vehicles, heavy machinery, oversized equipment, bulk commodities and other specialised shipments.
Why are containers so important to sea freight?
The standard shipping container changed international trade by creating a consistent way to pack, handle and transfer goods between different forms of transportation.
A container can move between a truck, rail service and cargo ship without requiring the individual goods inside to be unloaded at every stage.
Common shipping container types
- 20-foot general purpose containers
- 40-foot general purpose containers
- High-cube containers
- Refrigerated containers
- Open-top containers
- Flat-rack containers
What is the difference between FCL and LCL?
Two common approaches to containerised sea freight are Full Container Load (FCL) and Less than Container Load (LCL).
Full Container Load (FCL)
With FCL, a shipment uses an entire container. The container may be dedicated to one shipment even when the cargo does not physically fill every available space.
Less than Container Load (LCL)
With LCL, cargo from different shippers can share container space. This can be useful when a shipment does not require an entire container.
The appropriate option depends on factors such as cargo volume, handling requirements, destination, timing and overall transportation costs.
Why choose sea cargo?
Sea freight is one part of the wider international logistics system. Its strengths make it particularly useful for certain types of shipments.
Large Volumes
Cargo ships can transport substantial quantities of goods during a single voyage, making maritime transport suitable for high-volume international trade.
International Reach
Major ports and shipping routes connect markets across continents, linking Australia and the Pacific with Asia and the wider global economy.
Different Cargo Types
Modern maritime transportation supports many categories of freight, from standard containers to vehicles, refrigerated products and specialised equipment.
How much does sea cargo cost?
There is no single price for sea freight. The total cost depends on the characteristics of the shipment and the route between origin and destination.
Freight charges can be influenced by cargo volume, container type, origin port, destination port, shipping route, fuel costs, port charges, terminal handling, customs requirements and inland transportation.
Factors that can affect shipping costs
- Cargo weight and volume
- FCL or LCL shipping
- Container type
- Origin and destination
- Port and terminal charges
- Customs and documentation
- Inland transport
- Seasonal market conditions
Sea cargo across Australia and Papua New Guinea.
Geography plays an important role in regional maritime transportation. Australia and Papua New Guinea are separated by the Coral Sea and connected through a broader network of commercial shipping and trade.
Australian Shipping Network
Major Australian ports including Fremantle, Port Botany, Melbourne and Brisbane connect Australian trade with international shipping routes.
Papua New Guinea
Port Moresby, Lae and other coastal locations form part of Papua New Guinea's maritime environment and its connections with Australia and the Pacific.
How do sea cargo routes work?
A shipping route connects ports through a planned sequence of vessel movements. Some services operate between two principal ports, while others involve multiple ports and transhipment hubs.
Transhipment occurs when cargo is transferred from one vessel to another at an intermediate port before continuing toward its destination.
This means a shipment between Australia and Papua New Guinea, for example, may involve more than one vessel or port depending on the available shipping service and route.
What documents are involved in sea cargo?
International shipments require documentation so that cargo can be identified, transported, cleared and delivered through the relevant supply chain.
Bill of Lading
A Bill of Lading is an important shipping document associated with the carriage of goods by sea and contains information about the shipment and parties involved.
Commercial Invoice
Commercial invoices provide information about the goods, transaction and parties and can be relevant to customs procedures.
Packing List
A packing list can describe the contents, quantities, dimensions and packaging of a shipment.
“Sea cargo is more than a ship moving between two ports.”
Behind every shipment is a network of exporters, importers, freight forwarders, shipping lines, port operators, customs authorities, terminal workers, transport companies and logistics providers.
Sea freight terminology worth knowing.
Understanding the language used throughout the maritime industry makes it easier to research shipping options, compare information and communicate with logistics providers.
- Sea freight / Ocean freight
- FCL — Full Container Load
- LCL — Less than Container Load
- TEU — Twenty-foot Equivalent Unit
- Bill of Lading
- Transhipment
- Port of loading
- Port of discharge
- Shipping line
- Container terminal
- Freight forwarder
- Customs clearance
Explore the sea cargo network.
Sea cargo is a broad subject. Understanding the basic concept is only the beginning. The next step is exploring containers, shipping routes, ports, costs, transit times and regional maritime networks.
For readers interested in Australia and Papua New Guinea, the relationship between Australian ports and Pacific destinations provides an important regional perspective.
Callum Whitmore
Callum Whitmore writes about sea cargo, maritime transportation, shipping routes and ports, with a particular focus on Australia, Papua New Guinea and the wider Pacific.