Keel

From a structural view, a keel is a longitudinal member at the lowest point in the hull in continuous contact with water. If the longitudinal structural element is inside the hull, it is a keelson.

Most composite kayaks don't have a separate keel. The term is used in a more generic sense to describe the lowest part of the hull along the longitudinal centreline.

The keel affects the boats tracking. Generally the deeper and more pronounced the keel, the straighter the boat will go, and the harder it will be to turn.