Physics for Game Developers, 2nd Edition

Chapter 16. Ships and Boats

The physics of ships is a vast subject. While the same principles govern canoes and super tankers, the difference between the two scales is not trivial. Our goal in this chapter will be to explain some of the fundamental physical principles to allow you to develop realistic simulations. The typical displacement-type ship lends itself well to illustrating these principles; however, many of these principles also apply to other objects submerged or partially submerged in a fluid, such as submarines and air balloons. Remember, air is considered a fluid when we are considering buoyancy.

While surface ships or ships that operate on the water’s surface (at the air water interface) are similar to fully submerged objects like submarines or air balloons in that they all experience buoyancy, there are some very distinct differences in their physical nature that we’ll highlight in this chapter. These differences affect their behavior, so it is important to be aware of them if you intend to simulate such objects.

Ships have an entire language of their own, so we’ll be spending a lot of time just getting the vocabulary right. This will allow you to do further research on any topics that are of particular interest. There are many ways to classify ships and boats, but in regards to the physics governing them, there are three basic types. Displacement vessels, semi-displacement vessels, and planing vessels are named after the forces that keep the boat afloat while it is ...