Sea freight: definition, benefits, costs and challenges - Guide 2025

According to UNCTAD (Review of Maritime Transport), nearly 80% of the world's merchandise trade, in terms of volume, now transits by sea (or ocean). In 2025, this pillar of international trade is entering an era of unprecedented transformation: climate pressure, accelerated digitalization, rising logistics costs...

Yet behind every container lie major strategic challenges for companies. What are they? How can we control costs, reduce our carbon footprint and secure international flows? This comprehensive guide will help you to understand how sea freight works, its advantages, regulations and optimization levers, so you can navigate efficiently in tomorrow's global trade.

1. What is sea freight?
2. Why choose sea freight? Advantages and limitations
3. Sea freight and the environment: an impact to be monitored
4. Sea freight in figures (2024-2025)
5. The main players in sea freight
6. Sea freight regulations and challenges
7. Efficient sea freight management in the digital age
8. Conclusion
   
   
   
   

What is sea freight?

Sea freight refers to the transport of goods by sea (via the sea or ocean) on board commercial vessels. Its capacity in terms of volumes transported and its competitive cost make it the preferred shipping mode for international trade, particularly over long distances.

💡 Good to know: more rarely, sea freight can also involve military vessels chartered for humanitarian or logistical transport.

What types of cargo transit by sea?

Every day, all over the world, commercial vessels transport a wide range of goods. The main types of cargo include

• Containerized cargo: manufactured goods, electronics, textiles or consumer goods packed in standard 20- or 40-foot containers , i.e. around 6 to 12 meters long (1 foot = 30.48 cm).

💡 Good to know: in maritime transport, two standard formats are used as units of measurement for ship and terminal capacity. These are the TEU (Twenty-foot Equivalent Unit) and the FEU (Forty-foot Equivalent Unit). For example, a container ship that can carry 20,000 TEU is capable of loading around 20,000 20-foot containers or 10,000 40-foot containers.

• Dry bulk: unpackaged raw materials such as iron ore, coal or grain.
• Liquid bulk: any unpackaged liquid product, such as hydrocarbons, liquefied natural gas (LNG) or chemicals, transported in specially designed tankers.
• Ro-Ro (Roll-on Roll-off): vehicles, trucks or rolling stock loaded directly on board.
• Special cargoes, also known as outsize : industrialequipment (or machinery) , wind turbines or infrastructure requiring adapted vessels.

🔍 Definition: adapted ships are those designed to carry very heavy loads, known as heavy lift, and those designed to carry non-containerized or outsize goods, known as break bulk, i.e. goods transported piece by piece (crates, pallets or machines) and not in a container.

What types of sea freight vessels are there?

Each type of commercial vessel meets the specific requirements of a particular category of cargo:

• Container ships, as their name suggests, carry manufactured goods in standard containers;
• Ro-Ro ships load all types of rolling stock (cars, trucks, logistics equipment, etc.);
• tankers transport bulk liquids such as fuel oil or liquefied natural gas;
• Bulk carriers transport dry bulk goods such as cereals by sea.
  
  
  
  

Who are the players in sea freight?

The players in the sea freight sector form an entire ecosystem designed to ensure and secure the smooth flow of goods on a global scale. Three main profiles structure this international supply chain.

1. Shipping lines

The role of shipping lines is to operate ships and manage trade routes between charter ports. In concrete terms, this means planning itineraries, setting rates and guaranteeing the reliability of maritime links.

In 2025, the world's top 5 ocean carriers are as follows:

1. MSC (Mediterranean Shipping Company), an Italian-Swiss company that is now the world leader in container shipping.
2. Maersk, a historic Danish group, pioneering the digitization of logistics and integrated services (transport and supply chain).
3. CMA CGM (Compagnie maritime d'affrètement - Compagnie générale maritime), a well-known French company and one of the world leaders in container and multimodal logistics.
4. COSCO Shipping (China Ocean Shipping Company), a state-owned Chinese company and a major player in Asia-Europe trade.
5. Hapag-Lloyd, a German shipowner specializing in container transport and serving the world's major shipping lines.

Between them, these 5 companies account for over 65% of the world's container capacity, a figure that continues to rise.

2. Ports and sea terminals

These are the logistics hubs at the heart of this global traffic network. They handle the loading, unloading and storage of goods. Sometimes, they also organize the transshipment of certain goods. Infrastructures such as Shanghai, Singapore and Rotterdam are among the most efficient in the world, thanks to their automation and multimodal connectivity (rail, road, river).

3. Freight forwarders and logistics providers

Key intermediaries between shippers and carriers, forwarding agents and logistics providers coordinate customs operations, documentation and shipment tracking, from end to end of the logistics chain. Their digital solutions, such as TMS (Transport Management Systems), help optimize costs, lead times and flow traceability.

What are the advantages and disadvantages of sea freight?

There's no doubt about it: thanks to its many advantages, sea freight is the backbone of international trade. However, there are a number of limitations and constraints to consider before choosing it as your shipping mode. Let's take stock!

The benefits of sea freight

Shipping by sea is :

• economical: the average cost of a standard 20-foot shipping container is between 2,000 and 3,000 USD (U.S. dollars), compared with 15,000 to 20,000 USD for equivalent air freight;

• reliable, because the major shipping lines have organized global networks and advanced tracking systems that guarantee the traceability and security of shipments

• versatile, capable of transporting a wide range of goods in a secure manner, since containers enable sensitive products to be protected;

• scalable, because it can be easily adapted to the needs of all types of company, from SMEs to multinationals, whether for one-off shipments or large, frequent volumes.

The limits of sea freight

As advantageous as it may be, sea freight has a number of constraints that it's important to be aware of:

• Long lead times: sea journeys can last from a few days to several weeks, with potential stopovers, which requires rigorous planning and excludes products with short best-before dates.

• High dependence on ports: both loading and unloading depend on port infrastructures and capacities, which can lead to costly delays or blockages.

• Low flexibility: because of its slowness, this mode of transport is less responsive to last-minute changes, and offers fewer alternative itineraries than air or road freight.
  
  
  
  

What is the environmental impact of sea freight?

According to the latest scientific and sectoral estimates, sea freight currently accounts for between 1.7% and 3% of global anthropogenic greenhouse gas emissions. In absolute terms, these emissions have increased in recent years. The cause: traffic growth and the increasing size of ships.

In addition to CO₂, the sector generates other significant local pollution:

• emissions of nitrogen oxides (NOx)
• sulfur dioxide (SO₂) (depending on the quality of the fuel used)
• soot ;
• hydrocarbon discharges in the event of accidents
• plastic pollution
• waste from port activities and losses at sea.

Marine impacts are equally varied: degradation of coastal habitats, underwater noise affecting wildlife, pollution of the seabed by anchors and risks of oil spills in the event of accidents. If nothing is done, shipping's share of global emissions could grow - some analyses estimate that it could reach up to 10% of the total by 2050.

The decarbonization of shipping today relies on a stack of complementary solutions, as there is no "single solution" ready worldwide. Among the most promising avenues already being deployed by 2025 are :

• Alternative fuels: liquefied natural gas, as an intermediate-scale solution (with debates on fugitive methane), methanol (including biomethanol), green ammonia, hydrogen and biofuels, are at different stages of maturity. Some (LNG, methanol) are already seeing ship orders, while others (ammonia, hydrogen) are in the demonstration phase or early pilot projects.
• Operational optimization: slow steaming, itinerary rationalization, intelligent port call management and improved logistics planning immediately reduce fuel consumption. Studies show that a 10% reduction in speed can significantly reduce fuel consumption and the corresponding emissions.
• Propulsion and innovative energy aids: wing sails, Flettner rotors, electric-battery hybrids for short distances, energy recovery systems and on-board carbon capture projects in demonstration. Wind and aerodynamic assistance are particularly attractive, as they do not require a fuel supply chain.
• Infrastructure and the green fuels market: the rise of green bunkers (ammonia, e-fuels) requires investment in renewable energy production and port refueling capacity, a major lock in the ecological transition.

📝 Note: the IMO (International Maritime Organization) targets carbon neutrality " by or around 20 50", with intermediate milestones. The revised roadmaps call for indicative reductions in the order of 20-30% by 2030 (depending on the scenario) and around 70% (or even more, the " striving for 80% " ambition) by 2040, to then achieve net neutrality around 2050 - which implies a massive shift to new fuels, technologies and market mechanisms (pricing, incentives, standards, etc.).

Regulation of sea freight in 2025

Maritime freight is governed by a whole set of international rules. These aim to secure trade, protect the environment and harmonize practices between carriers, shippers and port authorities.

The main legal frameworks for maritime transport

Two main categories of rules govern maritime transport contracts:

• Hamburg Rules (1978): these define the responsibility of the maritime carrier in the event of loss, damage or delay.
• Rotterdam Rules (2009): modernize previous conventions to incorporate multimodal transport and electronic trading.

These rules serve as a benchmark for international contracts, guaranteeing greater protection for both shippers and carriers.

Incoterms for sea freight

Incoterms (International Commercial Terms) are standards drawn up by the ICC (International Chamber of Commerce) with the aim of defining who bears the costs, risks and customs formalities at each stage of transport: the seller or the buyer.

The most commonly used Incoterms for sea freight are :

• FOB (Free On Board): the seller bears all costs and risks up to the point of shipment.
• CFR (Cost and Freight): the seller pays for carriage to the port of arrival, but the risk passes to the buyer on departure.
• CIF (Cost, Insurance and Freight): similar to CFR, except that the seller also includes marine insurance.
  
  
  

These frameworks ensure a clear division of responsibilities and facilitate international transactions through a universal code known by all players in the supply chain. This standardization breaks down language barriers, which are very restrictive in international trade, to avoid disputes.

Key shipping documents

• Bill of Lading: essential document certifying ownership and receipt of goods on board.

• Packinglist : details the physical contents of the shipment, enabling customs authorities to compare it with the commercial invoice.

• Sea Waybill: simplified version, without transfer of ownership.

• Charter Party: a contract concluded for the charter of a full or partial vessel.
  
  
  

Current challenges facing the shipping industry

In 2025, sea freight is at a decisive turning point. Three main transitions are underway, forcing it to reinvent itself:

1. Sustainability: minimizing the environmental impact of logistics, reducing marine pollutants, developing green ports... all challenges that must be met to achieve carbon neutrality by 2050.
2. Digitization: terminal automation, real-time traceability, the use of advanced tools such as chartering software... for less costly and cleaner logistics, because they are more efficient and consume less fuel.
3. International governance: we need to strike a balance between national regulations and global standards to avoid fragmented rules.
   
   
   
   

Sea, air or road transport: how to choose?

The choice of transport mode depends on the type of goods, the desired delivery time, the budget and, for committed companies, theenvironmental impact.

This comparative table summarizes the differences between the three modes of transport.

📌 To sum up:

• Sea freight is ideal for massive volumes at optimized costs.
• Air freight is a premium solution for urgent deliveries.
• Road freight is an indispensable complement for final distribution or a no-brainer for local flexibility.

💡 Shiptify tip: combining several modes via a multimodal transport strategy often optimizes logistics costs and the shipment's carbon footprint, without lengthening delivery times.

How to manage sea freight efficiently with a TMS?

As you can imagine, sea freight involves a large number of players, and the management of various documents and deadlines. Without a suitable tool, tracking quickly becomes complex, with limited visibility of shipments, data entry errors and unanticipated delays, impacting customer satisfaction.

This is where the TMS comes in. This software centralizes all transport operations, from planning to traceability. Its mission? To simplify the day-to-day management of sea freight.

1. Easily plan and book shipments

The TMS facilitates the purchase of transport by comparing carriers' rates, capacities and lead times. You choose the best option according to your own criteria: cost, reliability, product constraints, durability, etc.

2. Automate documents and formalities

No more manual input errors! Key documents (Bill of Lading, packing list, certificates of origin, etc.) are automatically generated from your database and stored in a single, secure area.

3. Track your containers in real time

Thanks to GPS tracking and automatic notifications, you know where your cargo is at all times. As a result, you can offer your customers a proactive service that enables you to anticipate delays and optimize your transport plan.

4. Analyze and optimize costs

TMS-integrated dashboards provide a clear view, with precise performance indicators: costs per trip, load factor, carbon emissions, etc., enabling you to steer your logistics strategy with confidence. Precise management of your logistics strategy.