It is difficult to describe ‘correct’ sail shape, but the three most important things to consider are: sail draft (the fullness of the sail), draft position, and twist (controlled by the kicker / vang and leech tension).
SAIL DRAFT
Sail draft (chord depth) is an imaginary line from luff to leech called the chord. Chord depth can then be expressed as the ratio percentage between the maximum draft (d) and chord length (c). Draft stripes or seams in the sail can be used to estimate the depth. It
