The S2 10.3 is a recreational keelboat, built predominantly of fiberglass, with wood trim. It has a masthead sloop rig, a raked stem, a reverse transom, an internally mounted spade-type rudder controlled by a tiller and a fixed fin keel or shoal draft keel. It displaces 10,500 lb (4,763 kg) and carries 4,500 lb (2,041 kg) of ballast.[1][3]
The boat has a draft of 6.16 ft (1.88 m) with the standard keel and 4.92 ft (1.50 m) with the optional shoal draft keel.[1][3]
The design has sleeping accommodation for eight people, with a double "V"-berth in the bow cabin, two straight settee berths in the main cabin and two aft cabins with double berths. The galley is located on the starboard side just forward of the companionway ladder. The galley is L-shaped and is equipped with a two-burner stove and a sink. A navigation station is opposite the galley, on the port side. The head is located just aft of the bow cabin on the port side.[1][3]
For sailing downwind the design may be equipped with a symmetrical spinnaker.[1][3]
The design has a hull speed of 7.09 kn (13.13 km/h).[3]