[1][2] The design was built by Helsen Yachts in Saint Petersburg, Florida, United States, starting in 1974, but it is now out of production.
[1][3] Designed as a more compact version of the Helsen 22, the Helsen 20 is a recreational keelboat, built predominantly of fiberglass, with wood trim.
It has a masthead sloop rig with aluminum spars, a raked stem, a plumb transom, a transom-hung rudder controlled by a tiller and a retractable swing keel.
[1][4] The boat has a draft of 1.17 ft (0.36 m) with the keel retracted, allowing beaching, operational in shallow water or ground transportation on a trailer.
A forward-hinged cabin top increases the cabin headroom from 4.25 in (11 cm) with it closed to 5.33 in (14 cm) with it open.