[1][2][3] The Kirby 23 is a development of the Sonar, with a cabin modified for cruising use.

[1][3][4] The design was built by Ross Marine starting in 1985, with six boats completed, but it is now out of production.

[1][3] The Kirby 23 is a recreational keelboat, built predominantly of fibreglass.

It has a fractional sloop rig, a raked stem, a reverse transom, an internally mounted spade-type rudder controlled by a tiller and a fixed fin keel.

[1][3] The boat has a draft of 3.92 ft (1.19 m) with the standard keel and is normally fitted with a small outboard motor for docking and manoeuvring.