Sirius 31 Sailboat Review, Specs, and Listings

Design and Construction

The Sirius 31 is built on a solid hand-laid fiberglass hull, with a deck that is partly balsa-cored but solid around the important openings for rigging and deck fittings anchor. A floating teak deck sits over the structure, paired with a fixed windscreen that gives genuine protection forward. The yacht’s most distinctive underwater feature is a hump in the lines just ahead of the pronounced skeg — a shape the designer borrowed from whales to promote a well-behaved stall anchor. There is no inner GRP shell, so any incipient leakage shows itself early rather than hiding behind liner panels. Construction quality is very solid, and the timber work is of high quality throughout, from the cockpit details to the dark teak wall panelling below.

History and Production

After the first three hulls were built with the hump, an oil-price shock in 1979 delayed matters; production then ran from the early 1980s until 1991 anchor. Around 170 boats were completed in this hull form, with roughly 70 in the original configuration. A deck-saloon version using the same hull appeared later and proved popular. Most boats carry a lead keel, though briefly at the start cast keels were used — already epoxy-coated at the time.

Rig and Handling

The Sirius 31 is a masthead sloop with a 13.0 m mast, a 21.5 m² mainsail, and a 29.9 m² Genoa I, plus a 70 m² gennaker or spinnaker option. She was offered in three draught variants: a fixed keel at 1.65 m, a shoaler fixed keel at 1.35 m, and a ballast centreboard swinging from 0.9 to 2.1 m. At just under 4.3 sail deadweight she counts as a comparatively heavy cruising boat, yet owners report she needs only 3 Beaufort to get moving and then sails very well and stably above that, handling waves comfortably anchor. The skeg gives her notable stability, though period observers noted the rudder feels somewhat cumbersome. All control lines are led back to the deep, well-protected cockpit.

Accommodations

Below, the Sirius 31 shows beautifully finished wood everywhere, arranged around a large central table in classic saloon style. Long Plexiglas panes originally lit the interior; the builder later substituted three oval aluminium-framed windows, though the earlier glazing can still be found on some boats. Fixed doors stand in place of loose bulkheads, and a pull-out washbasin makes practical use of the wet room’s compact space. Above the starboard dog bunk, a pull-out navigation table suits paper-chart work. The companionway steps lift out to reveal the Volvo 2002 with dual-circuit cooling. The layout is well thought-out, though the passages read as somewhat dark.

Known Issues

Osmosis is not a concern on this design, and the boats are not known for it. The teak deck, however, deserves critical inspection — it is very often fitted and can suffer if neglected. Previous owners who cut subsequent openings through the balsa-cored deck may have left poorly sealed penetrations, a source of leaks. Old screwed windows can weep, and on centreboard versions the board’s function should be verified.

Refits and Ownership

The builder offered a stern extension as a retrofit kit at an owner’s request, and it remains available from the yard today. That extension built in a swim ladder and step, quieted the engine, and improved the under-power stall anchor. Because the original shipyard still exists, parts supply and repairs stay practical for owners.

The Verdict

The Sirius 31 is a very solid, harmonious cruising yacht with many strengths and few real weaknesses. She rewards the sailor who values accessible construction, thoughtful accommodation, and a stable sea manner over outright racing sparkle.

Pros

Unusual whale-inspired hull hump for controlled stall and skeg-derived stability
Solid hand-laid hull, no inner shell to conceal problems
High-quality timber interior with practical pull-out fixtures
Deck-saloon and stern-extension options supported by the original yard

Cons