A bulb keel is a type of keel used in sailing vessels, designed to improve stability and performance. It features a bulb-shaped extension at the bottom, which lowers the center of gravity and enhances the boat's ability to resist tipping. This design allows for better handling and speed, especially in various wind conditions. The bulb keel is commonly found on racing yachts and cruising sailboats. By increasing the righting moment, it helps the vessel maintain balance while sailing. This design is particularly effective in reducing drag, making it a popular choice among modern sailors and boat builders.