“Ballast keel” in Marine Glossary

A “ballast keel” refers to a heavy, typically elongated structure attached to the bottom of a sailboat’s hull, specifically keelboats and some larger sailing vessels. The ballast keel serves multiple purposes related to stability and performance.

The primary function of a ballast keel is to provide stability to the vessel. By incorporating a concentrated mass at the bottom of the hull, the ballast keel helps to lower the center of gravity of the boat, making it less prone to tipping or heeling over in response to wind or wave forces. This stability is crucial for maintaining the boat’s balance and ensuring safe sailing conditions.

In addition to stability, a ballast keel also plays a role in enhancing sailing performance. The keel’s shape and weight distribution help to resist leeway (sideways drift caused by wind) and provide lateral resistance, allowing the boat to sail more efficiently upwind. The depth and shape of the keel contribute to the boat’s ability to track straight and maintain a desired course.

Ballast keels can be constructed from various materials, such as cast iron, lead, or steel. These materials offer high density, which allows for a significant concentration of weight while keeping the keel relatively compact.

The design and size of a ballast keel depend on factors such as the size and type of the sailboat, intended use, and sailing conditions. Different keel designs, such as fin keels, bulb keels, or wing keels, offer varying degrees of performance and stability characteristics.

Overall, a ballast keel is an integral part of sailboat design, providing stability, resistance to leeway, and improved sailing performance.