Fastest boat for given sail area

The original speed sailing classes all limited sail area only-the boat could be as long and as wide as you wanted. Some boats within those classes have since placed limitations on beam and length(A Class Cat and C Class cat):

World Speed Sailing Records can be established in the following classes:

10 sq m (up to and including 10 sq m)
A Class (from 10 sq m up to and including 150 sq ft (13.93 sq m))
B Class (from 150 sq ft up to and including 235 sq ft (21.84 sq m))
C Class (from 235 sq ft up to and including 300 sq ft (27.88 sq m))
D Class (over 300 sq ft)

 

Ok so naturally aspirated sailboats... the foil assisted is semi-aspirated then