At just over 50 feet on deck, the 51 is a substantial ocean-going cruiser rather than a lightweight performance boat. The European Recreational Craft Directive recognises her as a Category A (Ocean) vessel. Her ballast-displacement ratio of 32.1 percent, displacement-length ratio of 182, and capsize screening figure of 2.04 point to a stable, comfortable passage-maker.
Design and Construction
The hull is built from solid, hand-laid glass-reinforced plastic. The deck uses a balsa core to maintain stiffness without adding unnecessary weight. Inside, a glassed-in structural grid—Jeanneau’s “matrix”—distributes rig and keel loads through the hull.
Rig loads are also handled by a sophisticated internal tie-rod system. Stainless-steel deck plates connect to high-tensile rods that run down to heavy brackets bolted directly to the main structural bulkheads.
The long sweep of coachroof windows sets the 51 apart both visually and structurally. Instead of heavy aluminium frames, large acrylic panels are chemically bonded to a recessed flange in the GRP.
The hull measures 42 feet 4 inches on the waterline and displaces 30,860 pounds, including 9,920 pounds of iron ballast. Its defining feature is an exceptionally wide 16-foot beam carried well aft. That width allowed Jeanneau to fit twin steering wheels, a genuinely revolutionary choice for a production boat of this size at the time.
Rig, Performance, and Handling
The Sun Odyssey 51 was delivered primarily as a powerful masthead sloop, with an optional inner forestay for offshore work. The sail plan includes a 513-square-foot mainsail, with a 54-foot-10-inch luff and an 18-foot-8-inch foot. A 555-square-foot 100 percent foretriangle has a 62-foot hoist and a 17-foot-11-inch base, bringing total sail area to 1,068 square feet.
A sail-area-to-displacement ratio of 17.3 places the boat firmly in the moderate-performance cruiser category rather than among featherweight designs. She isn’t a sparkling performer in light air.
Under power, an 80-horsepower Perkins or Yanmar drives the boat at a comfortable 7.5 to 8 knots at 2,200 rpm. Steering is through a spade rudder. Because of the beamy aft sections, the wide stern requires the boat to be sailed relatively flat for optimum control; that is a characteristic of the hull shape rather than a flaw.
Cockpit and Accommodations
The Sun Odyssey 51 was offered in two common interior arrangements: a four-cabin layout favoured by charter fleets and a more palatial three-cabin owner’s version.
The cockpit is expansive, with a fixed central table that serves as the hub for dining on deck. Below, a longitudinal galley to port provides extensive counter space and excellent refrigeration capacity. That layout has helped make the model a favourite among liveaboards. Water capacity of more than 200 gallons further supports that role.
Verdict
The Sun Odyssey 51 is a thoughtfully engineered late-1980s cruiser that balances interior volume with ocean capability. The Farr-J&J collaboration produced a beamy, stiff hull with genuine offshore credentials. Details such as the internal tie-rods connected to the main bulkheads, the glassed-in matrix, and the bonded acrylic windows show a builder pushing production-yacht sophistication forward.
She isn’t a lively light-air performer, but her comfort ratio of 26.9 and Category A rating support her credentials as a dependable passage-maker.
Pros
- Category A ocean classification, with a 32.1 percent ballast ratio and a 2.04 capsize screening figure
- Twin wheels and a wide-beam-aft layout that were ahead of their production era
- Internal tie-rod rig structure bolted to the main bulkheads for load management
- Expansive cockpit and longitudinal galley well suited to liveaboard cruising
Cons
- Spade rudder and wide stern require sailing the boat relatively flat for best steering
- Balsa-cored deck calls for careful moisture inspection as the boat ages
