In maritime context:
* The waterline is the line where the hull of a ship or boat meets the surface of the water. It's a crucial measurement in naval architecture and engineering, as it helps determine the ship's draft (the depth of the hull below the waterline), displacement (the volume of water the ship displaces), and stability.
* The waterline can also refer to a specific design feature on a ship, such as the waterline marks, which indicate the ship's maximum draft and loading levels.
In other contexts:
* Waterline can refer to the level of water in a reservoir, lake, or other body of water. For example, you might hear about the waterline dropping during a drought.
* Waterline can also be used metaphorically to describe a critical point or level of something, such as "the waterline of our financial stability."
To understand the specific meaning of "waterline," it's important to consider the context in which the term is used.
Can you provide more context about where you encountered the term "waterline"? This will help me give you a more precise answer.