C. Raymond Hunt Associates drew the lines. The result was a 37-foot sloop with a 30-foot-4-inch waterline, a 10-foot-10-inch beam, and a displacement of 14,000 pounds. A 6,000-pound lead keel gave her a ballast ratio near 43 percent, reflecting a settled, seakindly purpose rather than racing ambition.
Design and Construction
The hull is a single solid-fiberglass molding. The deck uses balsa core in low-load areas and plywood where stiffness matters. Hull and deck meet at a flange joined both chemically and with fasteners.
The lead ballast sits inside the keel cavity and is glassed over, while teak-and-plywood bulkheads are well tabbed to the hull. The rudder hangs behind a large full skeg on a beefy stainless shaft, with a foam core beneath thin fiberglass.
Above the waterline, the sheer has the gentle dip typical of the mid-1970s, paired with a nicely raked stem. Below, the forefoot runs aft into a sweptback fin. A rubrail was a welcome option.
Early boats used gate valves on the thru-hulls. From 1980, O’Day switched to bronze through-hull fittings—a useful clue when reading a hull’s age from its plumbing.
Rig and Sailing Qualities
By modern standards, the sloop rig has a low aspect ratio. Air draft is 47 feet, and the long boom carries a moderate 594 square feet of working sail. The deck-stepped, single-spreader mast has double lower side stays and stainless rigging with swaged terminals. If those original terminals remain, they’re living on borrowed time and need replacement.
Sail handling is straightforward. The mainsheet runs aft to a triangular block-and-tackle on the aft deck and is worked by a small winch. This gives the boat clean end-boom sheeting while keeping the companionway clear. Genoa tracks sit outboard of the cockpit, with turning blocks aft. Jiffy reefing and two reef points in the mainsail make it simpler to reduce sail when shorthanded.
Underway, the O’Day 37 tracks well and stays dry upwind. Owners say she sails comfortably on autopilot. She finds her best stride as the wind builds; in light air, she needs more coaxing.
Cockpit and Accommodations
The deep center cockpit, which one owner called cozy, gives a real sense of security. Its wheel pedestal does, however, crowd the threshold to the aft cabin.
Below, the compact galley lies to port. It has a two-burner alcohol stove, double stainless-steel sinks—one annoyingly shallow—and a fairly large icebox with modest insulation. A small chart table sits opposite.
The main cabin has opposing settees around a drop-leaf table. Teak joinery is simple but neatly executed, overhead grab rails offer useful handholds, and headroom is 6 feet 4 inches.
Forward, a V-berth with a filler cushion sits behind flimsy folding doors. It shares a compact but complete head, and a generous hanging locker stands to starboard.
The aft cabin is the boat’s defining space: a roomy athwartships double berth with storage beneath, plus a private, fiberglass-lined head and shower. This genuinely separate aft suite was central to the O’Day 37’s appeal.
Machinery and Tankage
The standard four-cylinder, 32-horsepower Universal diesel drives through a 2:1 reduction gear and uses fuel sparingly. The aluminum fuel tank held 28 gallons, providing close to 300 miles of range under power.
Engine-room access is available through the cockpit seat lockers and the aft cabin, but access behind both companionways is poorer than it ought to be. Reaching the stuffing box is genuinely difficult, though one owner addressed the problem by installing a dripless replacement.
Known Issues and Common Refit Work
Owners reported that the original hatches—and especially the plastic portlights—need upgrading and, in most cases, outright replacement. The flush forward hatch leaks. Some boats fitted with forward deck prisms or skylights also developed leaks around them.
The chainplates sit mid-narrow-side-deck and are awkward to reach from inside. At the bow, the cast single roller is slightly undersized.
Common early ownership jobs include replacing the swaged rigging, renewing the hatches and portlights, and fitting a proper bow roller. The difficult route to the stuffing box may also prompt refit work.
O’Day built hundreds of 37s before phasing out the model in 1984.
The Verdict
The O’Day 37 is a thoughtfully laid-out small center-cockpit cruiser that behaves like a sailboat, not a trawler with sails. She is stiff and seakindly, with a private aft suite that defined much of her appeal. Light-air performance is less convincing, however, and several access and sealing weaknesses require an owner’s attention.
Pros
- Genuine center-cockpit layout under 40 feet, with a large private aft double and head
- Solid-fiberglass hull, lead ballast glassed into the keel, and well-tabbed bulkheads
- End-boom mainsheet and aft-led controls help keep the cockpit clear
- Tracks well, stays dry upwind, and sails steadily on autopilot
Cons
- Original hatches and plastic portlights leak and need replacement
- Poor access to the engine and stuffing box
- Undersized single bow roller
- Original swaged rigging terminals need replacement
