Hull Form and Construction
Built entirely of fiberglass with wood trim, the Sun Odyssey 31 presents a hull with a raked stem and a reverse transom that incorporates a swimming platform — a detail that was still something of a luxury touch on a 30-footer in the early 1990s. The spade-type rudder is internally mounted and controlled by a tiller, a pairing that delivers direct, connected feedback and simplifies the mechanical installation considerably compared to wheel-steered alternatives of similar size.
Draft is available in two configurations. The standard fin keel draws 5.74 feet, while an optional shoal-draft keel reduces that to 4.76 feet, opening up shallower anchorages and tidal harbors that would otherwise be off-limits. Ballast runs to 2,650 lb against a total displacement of 6,834 lb, yielding a ballast-to-displacement ratio that reflects a consciously stable, upright-sailing character rather than a racier, tender feel.
Rig and Sailing Performance
The Sun Odyssey 31 carries a masthead sloop rig in the Bermuda tradition, with a foretriangle height just over 36 feet and a mainsail luff of comparable dimension. Total sail area reaches 415 square feet, split between a 223 sq ft mainsail and a nearly 192 sq ft jib or genoa, providing enough canvas to move the hull adequately in light to moderate conditions. Hull speed works out to 6.74 knots, which is the practical ceiling for coastal passages rather than a limitation in everyday sailing.
The masthead configuration means the headsail carries all the way to the top of the mast, so a well-sized genoa fills the slot effectively and powers the boat in lighter breezes. The tiller controls a spade rudder with a relatively short, responsive arc, which rewards attentive helming and penalizes inattention less than some contemporary wheel-steered designs.
Accommodation and Layout
Two factory interior arrangements were offered, and each makes different trade-offs for how the interior volume is divided. The first layout sleeps four across a V-berth forward cabin and a port-side double aft cabin, with the main saloon organized around a U-shaped settee and table. The galley runs straight along the port side amidships, equipped with a two-burner stove, an icebox, and a sink, with the navigation station aft of it on the same side. The head occupies the starboard side adjacent to the companionway — a logical, compact arrangement that keeps wet traffic close to the exit.
The second layout expands sleeping capacity to six berths by substituting two straight settees and a drop-leaf table in the saloon for the U-shaped configuration, and reconfigures the galley to an L-shape at the companionway. In this version the navigation station shifts to starboard opposite the galley, and the head remains in its starboard position. Either arrangement fits within CE Category 2 certification, indicating the hull is rated for offshore passages up to 200 nautical miles from shelter in significant wave heights.
Engine and Tankage
A Yanmar 2GM20 diesel provides propulsion for maneuvering, harbor work, and calms. The two-cylinder Yanmar is one of the more mechanically straightforward engines of its era: parts remain widely available, and the engine's reputation for longevity is well established among cruisers who keep up with basic maintenance. The fuel tank holds 12 U.S. gallons, which limits extended motoring range but is proportionate for a boat of this size and intended range. Fresh water capacity of 24 U.S. gallons is adequate for weekend cruising and modest coastal passages with two to four people aboard.
The Verdict
The Sun Odyssey 31 is a well-proportioned, purpose-built coastal cruiser from a period when Jeanneau was refining what a family-friendly production boat should look and sail like. Andrieu's design — bridging the Sun Light 30 and sharing its moment with the Sun Fast 31 — lands solidly in the middle: not a racer, not a heavy-displacement passagemaker, but a capable, honest cruising boat with enough beam and ballast to stay comfortable in a chop and enough accommodation to sleep a family for a week. The choice between shoal and standard keel allows owners to tailor it to their home waters.
Pros
- Masthead sloop rig with generous total sail area for efficient light-air performance
- Two keel options including a shoal-draft variant for restricted waters
- Dual factory interior layouts accommodating four or six berths
- Reverse transom with integrated swim platform
- Proven Yanmar 2GM20 diesel with strong parts availability
- CE Category 2 offshore rating
- Tiller steering with direct spade-rudder feedback
Cons
- 24-gallon fresh water tank is modest for extended cruising
- 12-gallon fuel capacity limits motoring range
- Production ended in 1997, meaning all examples are now several decades old
- Hull speed ceiling of 6.74 knots restricts progress in light-air or passage-making contexts
- Tiller-only steering may not suit all buyers, particularly those transitioning from larger wheel-steered boats
