Glossary · On-board systems
Water ballast
Also called: Ballast, ballasts, remplir les ballasts
A tank filled with seawater on the windward side to add weight and stability.
Ballast tanks are filled by pump or scoop, and emptied or transferred across at each tack. Placed to windward, they increase righting moment, hence power. Placed forward or aft, they adjust trim. They are the main adjustable source of power on a Class40.