[1][2] The design was built by Silverline Boats in Moorhead, Minnesota, United States, until 1980 when the company closed.

It has a lateen rig, a spooned, raked stem, a vertical transom, a rounded, transom-hung rudder controlled by a tiller and a retractable fiberglass daggerboard.

[3][2] The boat has a draft of 1.54 ft (0.47 m) with the daggerboard extended and 3 in (7.6 cm) with it retracted, allowing beaching or ground transportation on a trailer or car roof rack.

[2] In a 1994 review Richard Sherwood notes that the, "Dolphin is a lateen-rigged cat board boat, slightly longer than most.

"[2] Randle B. Moore wrote about the design in 2011, saying, "the Dolphin Senior is one of many small sailboats patterned after the world's most produced boat, the Sunfish.