Why Is Bilge Keel Important?

A bilge keel is a nautical device used to reduce a ship's tendency to roll. Bilge keels are employed in pairs (one for each side of the ship). ... Bilge keels increase hydrodynamic resistance to rolling, making the ship roll less. Bilge keels are passive stability systems.

Why is the keel important?

The keel is basically a flat blade sticking down into the water from a sailboat's bottom. It has two functions: it prevents the boat from being blown sideways by the wind, and it holds the ballast that keeps the boat right-side up.

How did a keel improve boat design?

First, it keeps the vessel on a straight course without adding drag or resistance. It actually counters it from coming from the sides to tip over or heel a boat. Second, added weight or ballast within the structure keeps the boat vertical and helps right it if it capsizes, providing an additional counterbalance.