[1] Racing boats (often called "shells") are long, narrow, and broadly semicircular in cross-section in order to reduce drag to a minimum.
The riggers in sculling apply the forces symmetrically to each side of the boat.
Double sculls is one of the classes recognized by the International Rowing Federation and the Olympics.
[2] In contrast to the combination of the coxed pair, in which the distribution of the riggers means the forces are staggered alternately along the boat, the symmetrical forces in sculling make the boat more efficient and so the double scull is faster than the coxless pair.
It is clinker built with fixed seats and thole pins and can be skiffed for leisure purposes or for the sport of skiff racing.