The S2 5.5, also called the Grand Slam 5.5, is an American sailing dinghy that was designed by Don Wennersten as a racer and day sailer and first built in 1982.
[1][2] The design was the smallest boat S2 Yachts produced and its only dingy model.
[3][4] The design was built by S2 Yachts in Holland, Michigan, United States from 1982 until 1983, with 70 boats completed, but it is now out of production.
It has a fractional sloop rig, a raked stem, a plumb transom, a transom-hung rudder controlled by a tiller and a retractable centerboard.
With it retracted the boat can operate in shallow water, be beached or ground transported on a trailer.