What is a retractable keel?

A retractable keel is a keel that can be retracted into a vessel's hull when not needed, making it easier for a vessel to sail in shallow waters or to manoeuvre more quickly. The keel may also be partly retracted to reduce drag and improve fuel economy when sailing at high speed.

The retractable keel is made up of several parts.

- The blade, which lowers into the water to improve water displacement and lateral stability.

- The trunk, which is the main part of the keel and houses the blade and lifting mechanism.

- The lifting mechanism, which raises and lowers the blade.

The lifting mechanism is usually hydraulic or electric, and can be operated from the cockpit. When the keel is retracted, it can usually be stored within the hull of the vessel, so it does not affect the vessel's profile or the ability to move freely in shallow water.

Retractable keels are often used on sailing boats and other small watercraft, such as catamarans and trimarans. They are also used on larger vessels, such as yachts and cruise ships, which may need to navigate shallow waters or canals.