Designed by Laurent Giles in 1970 the Jouster and the Warwick were two 21 footers built for the offshore racing fraternity and the cruising fraternity respectively. The Jouster was a successful design with many wins in its class. Although being a pure racer, it had a somewhat bare cabin layout, it did also double as a weekend sailer. It was also a lot cheaper than the Warwick.
By later years the interior had become significantly more luxurious, with full headlining. The rig was also reduced slightly in size to make the Jouster a little less hairy for the cruising sailor: the later mainsail was about 12" shorter in the foot and the luff than the original racing version.
Westerly Jouster Brochure here: Westerly Brochures