A fin keel is a type of keel used in sailing vessels, designed to enhance stability and performance. It consists of a vertical fin that extends downward from the hull, with a weighted bulb at the bottom. This design helps to lower the center of gravity, improving the boat's balance and reducing the risk of capsizing. Fin keels are commonly found on modern racing and cruising yachts, as they allow for better maneuverability and speed. Compared to traditional full keels, fin keels are lighter and provide less drag, making them ideal for competitive sailing.