The small production run makes the 300 MS a rare sight, but her purpose is clear. She’s a short-handed coastal cruiser that favors shelter and steadiness over athletic sailing.
Design and Construction
The 300 MS has a long, full keel and a high cabin trunk. Her 11-foot-5-inch beam carries almost to the stern, creating useful space below. The side decks are deliberately narrow to maximize interior volume, while handrails run aft along the high cabin trunk to the pilothouse roof. Large hatches in both the cabin top and pilothouse provide ample ventilation. At the bow, a teak anchor platform sits on a molded fiberglass structure that forms part of the small foredeck.
The hull is solid fiberglass. Its 4,500 pounds of lead ballast is encapsulated in a long, shallow keel, with the propeller set in a large aperture ahead of a relatively small attached rudder. Displacement is 11,500 pounds, for a ballast-to-displacement ratio of 39.13 and a comfort ratio of 25.22. Those figures suit a boat intended to remain steady in a seaway rather than win buoy races.
Rig, Sailing, and Handling
The 300 MS is a masthead sloop with a traditional single-spreader rig. Halyards terminate at mast-mounted winches. A traveler forward of the mast accommodates a self-tacking jib, while genoa tracks on the toe rail allow for a larger sail.
Reported sail area is 442 square feet, with a sail-area-to-displacement ratio near 14. That makes her no light-air performer. As the breeze builds into the 10- to 15-knot range, however, she settles in, tracks well, and makes steady, comfortable progress. Hull speed is just shy of 7 knots.
The full keel helps the boat track straight, easing the workload at the helm. The trade-off is less-than-stellar maneuverability in marinas or tight anchorages.
Under power, the Westerbeke 46 diesel produces 46 horsepower and burns roughly a gallon per hour. Cruising speed is about 6 to 6.5 knots, with as much as 7.5 knots available in a hurry. The wide beam and flat run aft help reduce stern squat under power.
Pilothouse and Accommodations
The pilothouse is the heart of the boat, offering excellent visibility through real glass rather than hazy plastic. Its forward bulkhead is formed by the lockable companionway. The pilothouse was originally open aft to the cockpit, though most owners have since enclosed that end with canvas or a solid partition.
Below, the layout favors living space. An expansive galley to starboard includes a two-burner stove, a large icebox, and the boat’s 75-gallon water supply. To port, the dinette converts into additional sleeping space.
Forward, the V-berth is generous for a boat of this length, with a hanging locker to starboard. The head to port is functional. With the beam carried well aft, the interior feels larger than its 30-foot envelope suggests.
Known Issues
Pilothouse windows are a recurring topic among owners, usually because of potential leaks or aging seals. The steering system also warrants careful inspection, including confirmation that the emergency tiller is present and usable.
Otherwise, owner discussions are notable for the absence of widespread structural concerns. The full keel’s tight-quarters handling limitation remains another principal drawback.
Refits and Ownership
Many owners have modified their 300 MS so that all sail controls lead back to the pilothouse, reducing the need to go forward in bad weather. Enclosing the aft end of the pilothouse is another common and practical modification.
One documented refit illustrates the kind of major work and equipment a buyer may encounter. Its Westerbeke 46 was rebuilt in 2016, and the boat carried a newer mainsail, roller furling, a serviceable jib, about 300 watts of solar, and a manual foredeck windlass. That combination suggests attentive ownership.
The Verdict
The Cape Dory 300 MS is a deliberate motorsailer: slow to accelerate and stiff to pivot in a slip, but secure, forgiving when the wind fills in, and roomy for her length. She best suits a coastal cruiser who values a warm pilothouse and steady helm more than sparkling sailing performance.
Pros
- Pilothouse with real-glass visibility and a rare enclosed-helm option
- Beam carried aft provides uncommon interior volume for a 30-foot boat
- Lead-ballasted full keel and 39% ballast ratio promote steady tracking
- No widespread structural defects reported across the small fleet
Cons
- Full keel makes maneuvering in marinas and tight anchorages awkward
- Sail-area-to-displacement ratio near 14 leaves her sluggish in light air
- Pilothouse window seals are a recurring leak concern
- With only 47 built, finding a boat and model-specific parts knowledge takes patience
