Marine Cadet

What is the sea chests on the ships?

By: Marine Cadet | Last updated: Sun Jan 08 2023

In ships, sea chests are nothing but a suction point/port. The first stop of seawater before it is included in the ship’s body is sea chests. Think of it as a vast reservoir, one side open to the sea, and on the other side, a pipeline opens to the ship. I hope the image we prepared below will make your understanding more accessible.

sea chest sketch marine cadet

Is that all? Of course not; let’s get down to the details now.

We know that sea chests are the doors that allow the ships to take water from outside. So how can this system deal with a possible blockage?

What can clog? Don’t ask; we’re talking about the sea. Everything can happen if there is a big fish, sea litter, or shellfish blocking the hole. On the outside of the sea chests, some grids prevent large objects from entering the pipes and clogging them up. These grids are perfect for avoiding severe system blockages.

Well, as we mentioned above, what do we do if the shellfish chokes?

This is where MGPS (marine growing protection system) comes into play. The working logic of MGPS is not the area of interest of this subject; in short, it is enough to know that it prevents the formation of living things and crustaceans.

We can now give the seawater waiting to be absorbed in our sea chest to the ship’s body. Sea chests need to be closed in some cases; for this, at least one valve is placed on the suction pipe. Thus, we can turn off the water in different scenarios, such as in open seas, ports, or possible cleaning operations.


Sea chests are a part of a ship’s body that is located bottom of the water line, and their primary purpose is to become a gateway to let sea water inside the vessel.