Sirius 40 DS Sailboat Review, Specs, and Listings

Design and Construction

The hull is hand-laid fiberglass, built in a one-piece mould with vinylester gelcoat and resin, fibreglass mats and rovings, and above the waterline a vacuum-adhered Corecell M-foam sandwich for stiffness without excess weight. Parts of the deck use foam-sandwich construction as well, and the hull-deck connection and all bulkheads are laminated from every side so the structure reads as a single monocoque. The keel carries about 3.45 tonnes of cast iron—or an optional hardened lead bulb—glued and screwed to the hull with fourteen 20 mm stainless steel bolts through steel reinforcement, and the loads are spread by massively laminated bottom floor sections. Underwater finish is one layer of epoxy primer and hard antifouling with two waterline stripes in the owner's chosen colour. A deck-saloon reviewer in 48° North found a massive steel rod tying a deck fitting directly to an athwartships stringer in the midship cabin closet, a detail that underscores how the semi-custom hull is engineered for real offshore loads.

Keel and Draft Options

What sets the 40 DS apart is the array of ballast arrangements. The standard single fin draws 7.5 feet, with optional fixed shoal versions at 6.6 and 5.7 feet, but the more interesting choices are the swing keel and twin keel. The swing keel is a real centreboard that moves all the ballast up and down, giving a draft range from about 3.1 to 8.0 feet; its box is an integral laminated part of the hull, and the builder describes the mechanism as very reliable and safe yet complex. The twin-keel version, by contrast, lets the boat sit upright on tidal flats daily rather than as a novelty—48° North sailed that configuration and reported it structurally strong and stable enough to support the boat and its contents on land twice a day in perpetuity, with no compromise in sailing performance or tacking angles versus the fixed keel.

Rig and Handling

The boat wears a 2-spreader Selden mast of aluminium with a furling forestay and a self-tacking jib system, paired with a traditional-sheeting genoa in Solent-rig fashion as one reviewer noted. All active halyards and trim lines run aft to the cockpit through stoppers into a halyard box served by a single self-tailing winch, so short-handed sailing is practical. The main boom carries two single-line reefing systems and a kicking strap, and a carbon-performance rig is offered for those chasing pace. With a sail-area-to-displacement ratio near 4.0 on the self-tacking jib and 4.8 with genoa, the design is no light-air rocket, but the broad beam and 15.9 SA/D keep her honest upwind and reaching. Steering is by a pre-balanced half-skegged rudder on a burly centreline-hinged wheel, and an interior helm station lets the crew steer from the saloon in foul weather.

Accommodations

The deck-saloon layout is the heart of the boat. A raised dinette to port and a large saloon that seats six adults around an extending table exploit the 360-degree glazing and 1.95 m headroom, while the double-use of raised and lower space gives more room than expected on any 47-footer. Owners have requested more than eight interior plans—from 2+2 to 6+2 berths, a lower-lounge version, or an office—and the builder claims both a large workshop and a large central cabin are possible together, a first for Sirius. The mid-ship berth tucked under the saloon on port offers one of the largest double bunks afloat and the least boat motion; the aft-most dinette bench hinges away to reveal a passage into a hidden shop and systems room with a workbench, entered directly from an aft cabin in some layouts. Deep underfloor compartments—nearly three feet down in front of the galley, four in total—swallow provisions and spares. The galley itself runs to a two-burner half-gimbaled stove with oven, 130-litre fridge, double sink and pressurized water, while two heads and 400-plus litres of water tankage suit extended living aboard.

Ownership and Refit Notes

Every Sirius 40 DS is custom built to the owner's specific requirements, a pure semi-custom boat, so no two are fitted identically; the builder offers personalised onboard and deck stowage beyond expectation. Standard equipment is generous—Rocna anchor with 50 m of calibrated chain and electric windlass, Flexiteek cockpit, fold-down transom door, and a Volvo Penta D2-55 saildrive with 53-gallon diesel capacity per spec. The swing keel's complexity is the one system a buyer should plan to understand and maintain, but the twin-keel and fixed-keel variants avoid that entirely. Torsten Schmidt, owner of Sirius, spent seven weeks living aboard non-stop, a signal of how the firm views the boat's liveaboard credentials.

The Verdict

The Sirius 40 DS is a thoughtfully engineered semi-custom cruiser whose deck-saloon volume, flexible layouts, and genuine drying-out or shallow-draft options are rare in a 40-foot bluewater hull. She is solidly built and comfortably appointed for long passages, though the swing keel demands respect as a complex system.

Pros