Design and Construction
The Tempest 31 is a moderate-displacement monohull with a ballast-to-displacement ratio of 29.8 and a displacement-length ratio of 274, figures that place it among coastal cruisers rather than light-displacement racers. Its 2,690 lb ballast is carried in iron, and the standard fin-keel version draws about five feet; a bilge-keel option was offered with twin well-angled keels with bulbs at the base to keep the center of gravity low, plus slightly more keel weight than the fin version. The hull is solid fiberglass, and the deck is likewise solid glass. Compared with the earlier Fulmars — boats conceived as racing-capable — the Tempest received higher-quality joinery, a reflection of its repositioning toward the cruising family market rather than the regatta.
Rig and Handling
As a masthead sloop the Tempest carries a sail-area-to-displacement ratio of 14.8, which marks it as somewhat underpowered against high-performance designs but entirely in character for a comfort-oriented coastal cruiser. The capsize screening score of 2.1 and a comfort ratio of 22.2 reinforce that coastal profile. The theoretical hull speed is 6.6 knots, and the wetted surface runs about 290 square feet. Standing rigging and sheet estimates from period data list a 12 mm diameter for jib, genoa, mainsheet, and spinnaker sheets, with the mainsheet longest at just over 76 feet — useful context for an owner re-rigging, though these are database estimates rather than builder specifications.
Accommodations
The original layout slept up to six across three cabins: two spacious double aft cabins tucked under the cockpit and a forward V-berth cabin with access to the sail locker. Most boats sold were this twin-aft "Original" version. At the end of 1988 Westerly introduced the "Classic Option," substituting a single larger aft cabin with aft heads and a conventional V-berth forecabin, and gaining a much larger cockpit locker in the trade. Both layouts served the family-cruiser brief; the choice came down to whether the owner valued separate guest quarters aft or stowage and a bigger head.
The Verdict
The Tempest 31 is a small, finite-production Dubois cruiser that traded the Fulmar's race bias for broader aft sections, better joinery, and a genuinely usable three-cabin (or large-single-aft) interior. Its ratios mark it as a moderate-displacement coastal boat, not a bluewater greyhound, and the bilge-keel variant extends its grounding tolerance at the cost of a little more keel weight. With just over 100 built and a short successor run, it remains a comparatively scarce but well-documented Westerly. In 1993 the hull design, interior, and rig were reworked and renamed the Regatta 310, which nominally remained in production until 1997 with only five built.
Pros
- Dubois performance-cruiser pedigree with broader aft sections than the Fulmar
- Two distinct interior layouts, both sleeping six, with the Classic Option's large cockpit locker
- Moderate displacement and 2.1 capsize screen suit settled coastal cruising
Cons
- Sail-area-to-displacement of 14.8 leaves it underpowered next to modern performance boats
- Only just over 100 built; scarce on the used market
- Bilge-keel version carries more keel weight, trading some fin-keel balance
