1. The bottom of a body of water: This is the most common usage. It refers to the seabed or the ocean floor. For example:
* "The ship ran aground on a sand bed."
* "The divers explored the coral reef bed."
2. A layer of something at the bottom: This can refer to a layer of sediment, sand, or even a layer of fish at the bottom of a body of water.
* "The seabed was covered in a thick bed of seaweed."
* "The trawler caught a large bed of herring."
3. A specific type of ship's structure: In some cases, "bed" can refer to a specific part of a ship's structure, such as the bed of a barge or the bed of a ship's hold.
* "The barge had a flat bed for carrying cargo."
* "The ship's hold was filled with a bed of coal."
It's important to understand the context in which "bed" is used to determine its meaning in maritime English.