Design and Construction
The S31 was built by Marine Projects with a solid fiberglass hull and balsa-cored deck from that era, twin keels, and a skeg-hung rudder. Her 10,617-pound displacement and 3,650-pound iron ballast give a 34.38 ballast-displacement ratio, placing her in the moderate-ballast cruiser camp. A displacement-length ratio of 254.4 shows a volume-driven design.
Accommodations
The huge aft cabin stretches right across the full width of the boat, and even with its full-size double berth there is still plenty of space. That cabin has its own hatchway to the cockpit. The forecabin sleeps two and the saloon settees provide two more berths, for six total.
Rig and Handling
The S31 is a masthead sloop with 422 square feet of sail area. Her 19-horsepower Volvo Penta MD2020 diesel uses a saildrive. Period test reports from Yachting Monthly, Yachting World, and Yachts & Equipment in 1994 documented her launch behavior. The folding transom centre section drops to form water-access steps.
Known Issues
The saildrive leg on the MD2020 is a sealed underwater unit whose rubber boot and shaft seal are the wear points to understand on this design.
Ownership
The folding transom steps are a wear item in frequent swimming use but straightforward to maintain. With 145 built, the fleet is small.
The Verdict
The Moody S31 is a compact cruiser trading sportiness for a full-beam aft cabin and practical layout, best for couples or small families valuing volume and twin-keel flexibility.
Pros
- Full-width aft cabin with cockpit hatchway and ample space
- Six-berth layout with forecabin and saloon settees
- Solid hull with balsa-cored deck
- Folding transom steps to the water
Cons
- Saildrive needs seal and boot attention
- Small fleet limits choice
- Moderate ballast favors comfort over pace
