Masthead float

Catamarans and trimarans, being normally unballasted, float with great

stability either way up. A float at the masthead should prevent the im­mersion

of the mast, and thus ensure that the craft never gets into the stable, in­verted

attitude. Some floats are made of lightweight foamed plastic, or are

air-fIlled hollow chambers. Others are bladder-like, to be inflated

automatically from a carbon dioxide cylinder if the boat goes beyond a certain

angle of heel.