skin girth

It differs from the skin girth which is measured following the surface of the hull.

Skin girth is a measurement of a yacht hull.

Skin girth is measured by following the surface of the hull from a given elevation on the hull vertically from a specified fore-and-aft position.

Skin girth is specified in some design rules to handicap or match the capabilities of sailing vessels of similar design such as the 12 metre boats.