Is My Container Seaworthy? (Or Not)

Container Water Damage

In most sea export cases, the containers used for loading and transportation are carrier owned containers (COC) as to shipper owned containers (SOC). For freight transportation arranged with COC containers, the shipper relies on the carrier in providing seaworthy containers. However, what makes a container seaworthy? More importantly, do shipping liners always provide a seaworthy container?

In this article, we will guide you through some indicators that a container is truly seaworthy. In addition, provide some general ideas on what to do in the event that the container is unseaworthy.

Tip 1: Check Container CSC Plate

All containers, particularly COC containers are mandated to have a CSC plate welded onto the container, at the front door of the container.

CSC Plates are required by the International Maritime Organization (IMO) to ensure a safe environment for logistics service providers to operate the containers.

The IMO also tries to protect the interest of the container leasee by giving the cargo owners the peace of mind that the cargo loaded is safely protected from the external forces.

This is what a CSC plate generally looks like.

Every detail of the container is carved onto the seal, since its much more durable than stencilling important information on the plate.

But as an exporter, the one detail that we have to be aware of is the ACEP number.

ACEP stands for Approval Continuous Examination Program.

According to the BIC Code or the Bureau International des Containers (In italic because it’s *French*)

“containers operated under ACEP must be properly and regularly inspected as part of their regular operation and at a very minimum, within the intervals required under PES. Containers operated under an ACEP scheme must display the scheme number on the CSC plate; this is often in the form of a decal.”

ACEP requires that the containers are maintained periodically under the Periodic Examination Scheme (PES), which is not dissimilar to vehicle service inspections, the first inspection is 5 years after the manufacturing date, and subsequently once every 30 months.

Again, back to the vehicle inspection analogy, you won’t feel safe driving a car that has not been inspected for road safety. So, why would you trust your cargo with a container that is not inspected regularly?

Therefore, in practice, always look at the CSC plate’s ACEP examination date before loading the container. The more recent the examination date, the more indicative that the container is deemed seaworthy.

On the other hand, if you notice that the container’s last inspection date is more than 5 years ago. It is safe to assume that the container is not considered seaworthy. At least in the eye of the BIC organization.

Tip 2: Look Out for Noticeable Container Rust

Shipping containers are made of corrugated rolled steel that is sandblasted and coated with anti-rust or anti-corrosion paint.

However, constant exposure to the sea makes the container more prone to rust. After all, seawater corrosion rates on surface materials are much more rapid as compared to water.

The first reference point of container seaworthiness is always the CSC plate, which indicates the last inspection date.

Naturally, any noticeable rusts, that will impact the structural integrity of the container will be resurfaced.

But with that being said, not all container rusts will negatively impact structural integrity, or render the container not seaworthy.

Minor corrosion are normal in any container. Instead, we should be aware of major rusts that exposes the container with holes.

An exporter can physically inspect the external structure of the container to see any noticeable container rusts.

Rusty Container is not seaworthy
Excessively Rusted Container; Image Source:

The next step is to go in the container, and close the container door enough to not let too much sun in. If you see any sunlight escaping into the container from the top, it generally means that the container is rusted at the top side.

For cargoes that are sensitive to heat and water, that rusted container is not suitable to use.

Then again, if you are transporting durable machinery or steel coils, this should not be a big concern.

Tip 3: Understand What Your Cargo Needs

In tip 1, we explain that we should look at the CSC plate to determine whether regular inspections have been done on that container.

But truthfully though, not every shipping line are compliant to the IMO’s International Convention for Safe Containers.

Here is an excerpt from IMO: –

“The subsequent maintenance of a safety‑approved container is the responsibility of the owner, who is required to have the container periodically examined.”

This indicates that the IMO does not regulate container examinations. They certainly do not have the resources to do so. More importantly, there is not even an official record of how many numbers of the container there is circulating the world, only shipping liners know the exact figure.

Another noteworthy information is that even shipping liners lease containers from leasing companies to use. So, it gets complicated for regulators from contracting states to ascertain who is the owner of the container.

Since the IMO has left it to the shipping liner’s volition for container examination, we cannot assume that every shipping liner is operating with the same ethical code.

So, to summarize: –

  1. IMO’s CSC Convention does not regulate container examinations.
  2. Regulations are in place for container inspections, but not compliance.
  3. Not all SOC containers are “owned” by the shipping liners.

Therefore, there are times in our career in logistics and supply chain that we have to be content with what conditions the containers are in.

Accepting “Less” Seaworthy Containers

To work around this conundrum, we have to gauge whether the shipping container is up to the job. The work-around is to logically look at our cargo’s transportation requirements.

If you are transporting perishable goods such as vegetables, and you require a reefer container. You cannot depend on a reefer container that is littered with holes everywhere in the container.

But, as we have mentioned also in tip 2, if you are transporting sturdy cargos like steel coil or scrap metals, we can bear with small dents and nicks around the container.

For exporters, chances are you are already experienced and understand the nature of your cargo, and how tolerant the cargo can be for cargo that is less seaworthy.

This may not sound like advice; which is to “bear with the unseaworthiness of the container”, but sometimes normal business requirements and time restraints do not allow us the luxury to choose our containers. Therefore, we need to have a degree of tolerance for a sea container conditions.

Tip 4: Watch Out for Container Dents

Container dents can be caused by external forces and internal forces.

If it is an external force that damaged the container, the container will be dented inwards. Conversely, if the container is dented outwards, it is caused by insecure stowage and lashing of the cargo, causing the cargo to move about in the container and damage the container.

Container dents generally do not jeopardize the structural integrity of the container. But what a shipper should look out for is dents that occur on the frame of the container.

Besides, some container dents are not visible. For example, containers that have a hard time securing onto the trailer’s twist locks are indicative that the container is not fully perpendicular, which makes the container structurally compromised and therefore not seaworthy.

The image on the left has excessively bulged containers which makes the container not seaworthy; whereas minor dents on the right are not much cause for concern.

So, one practical tip for shippers is to see if twist-locking the container onto the trailer or detaching the container from the trailer is difficult. A seaworthy container should come in perfect rectangle shapes.

Twist Lock on Trailer
If containers are bent out of shape, making it difficult to twist-lock onto the trailer, it indicates the container is not seaworthy

Tip 5: Inspect the Container Floorboard

One of the most overlooked aspect of the container is the container floorboard.

A container floorboard is made of wood that is bolted onto the base frame of the container.

Container Floorboard

There should not be any dents on the container floorboard. If you notice any small dents on the container floorboard, it generally means that the floorboard is old or compromised and may not be able to withstand the weight of the cargo.

On an unrelated note, understanding the make of a shipping container also helps to understand what makes a container seaworthy or not: –

This is by far the most important feature of a cargo container, which is to be able to carry heavy cargos (within limits). A compromised floorboard renders the container completely unseaworthy.

Additional Reading: What to do if there is Cargo Damage

Other Tips

Here are other tips to ensure the cargo container is seaworthy: –

Faulty Door Handle
Rusty Door Lever; Image by TheUjulala from Pixabay
  • Ensure rubber seals are pliant and unworn
  • Ensure that the door assembly has a functioning locking system
  • Ensure that the container weld contact points are not compromised


Hello! I'm Kelvin, I work as a custom broker and I'm thrilled with having the experience to share my industry knowledge with you. I hope that you enjoy reading them as much as I do posting them.

3 thoughts on “Is My Container Seaworthy? (Or Not)

  1. Hello Mr. Kelvin, my name is George and I have 2 containers of 20 ft. full with my personal goods to be shipped to Romania for Repatriation in my country for retirement purpose.I need Seaworthy Certificate to provide to the shipping line as they required. I live in Marysville, Washington 98270. Please let me know how can I get the Seaworthy Certificate before the sailing time of December/20/2020.Thank you very much, George Andreil

    1. Dear George,

      It is unlikely that you have to use your own shipping containers for your personal effects.
      Normally your freight forwarder will arrange the container for you.

      To make sure your container is seaworthy, you need to highlight that you request seaworthy containers for loading,

      To check that you can refer to the CSC plate on the container itself

      Hope this helps George and good luck!

  2. Hello,
    My company is shipping our own container to Zambia with donations to the local school.
    How can I get a Seaworthy Certificate for this container? It is required by my logistic company in order to get the booking, but our container was purchased without such a certificate.

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