Keelklasside
Keelklasside is a term used in naval architecture and yachting discussions to describe the classification of keels, the underwater fins or ballast structures attached to a hull to provide stability. The phrase appears in several languages with similar roots and is not standardized in international nomenclature; in English-language texts the concept is usually referred to as keel types or keel designs.
Typical keel classes include full keel, fin keel, lifting keel, wing keel, bilge keel, and twin keel.
The choice of keel class affects stability, righting moment, wetted surface, ballast distribution, draft, and cost.