Glossary · Keels, foils & rudders
Keel bulb
Also called: Bulbe de quille, bulbe, torpille, bulb
A streamlined lead weight at the bottom of the keel, putting the ballast as low as possible.
Shaped like a torpedo, the bulb puts several tonnes of lead at the end of a thin keel fin. The lower the weight, the better it rights the boat. On an IMOCA it accounts for a large share of the boat's total weight.