Design and Construction
Seamaster Ltd. was among the largest British boat builders of the 1960s and 1970s, and the 815 belongs to the newer Holman & Pye range that broke from the traditional lines of the earlier Laurent Giles designs. The hull is fibreglass, with iron fin or twin iron bilge keels and a transom-hung rudder. At 26' 9" overall with a 21' 0" waterline and 8' 11" beam, the 815 is a moderate-displacement hull at 3.17 tons — and notably heavier than the slightly longer and beamier, but very similar looking, Moody 27. The choice of fin or bilge keels (4' 6" or 2' 11" draught respectively) lets the owner trade upwind bite for drying-out capability, and the documented reputation for tough construction carries forward from the early Seamaster sailing range into this modern-styled hull.
Rig and Handling
The 815 is a masthead sloop, and the sail plan is generous enough to give good performance despite the moderate displacement. The standard mainsail is 117 square feet with a 152-square-foot No 1 jib, while the optional light genoa and No 1 genoa both extend to 257 square feet; a No 2 genoa at 216 square feet and a 54-square-foot storm jib round out the working inventory, and an optional spinnaker was offered. With a Sail Area/Displacement ratio of 11.91 and a theoretical maximum hull speed of 6.1 knots, the design sits in the heavy-cruiser category by displacement-length ratio (342) yet remains lively on the wind. The capsize screening value of 1.86 and a Motion Comfort Ratio of 26.0 — more comfortable than 82% of similar designs — speak to a settled sea manner in a 26-footer.
Accommodations
Inside, the 815 presents a simple but quite spacious interior that is light and quite open, divided into a saloon and forecabin with 4/5 berths. Maximum headroom is about 5' 10". The saloon table is removable to open up space in the interior, and can also fit lower to extend the port settee berth into a nominal double that is wider at the forward end than the aft end. Practical Boat Owner described the boat as a tough and roomy little cruiser, and the open plan with flexible berthing explains that verdict without resorting to superlatives.
Known Issues
The source material records no structural or systemic defects for the 815 beyond the realities of its keel and engine configurations. The iron fin or bilge keels are subject to the usual corrosion vigilance any iron ballast demands, and the original Yanmar YS8 (8 BHP) or the 8/12 hp Yanmar installations are long past first youth; one documented example had its engine replaced by a 12 hp Yanmar YSB12. No flooding paths, drainage failures, or reinforcement deficiencies are documented in the source material.
Refits and Ownership
Ownership refit history centers on propulsion. The usual engine fitted was an 8 hp Yanmar, with 12 hp units also recorded from new, and the illustrated boat's swap to a Yanmar YSB12 shows the path many have taken. With 136 built and production closing in 1981 at the builder's cessation, the 815 is a finite and coherent class — a Holman & Pye design with a modern silhouette, tough construction, and a practical, open interior that has aged into a recognizable British cruiser.
The Verdict
The Seamaster 815 is a considered piece of late-1970s British design: a small cruising yacht that modernized the Seamaster look without abandoning the builder's tough-construction reputation, and that earns its roomy press notices through a genuinely open and flexible interior.
Pros
- Modern profile versus chunky contemporaries, with retained reputation for tough construction
- Light, open, simple interior with removable saloon table and flexible double berth
- Moderate displacement with enough sail area for good performance; comfortable motion profile
- Choice of fin or bilge keels for cruising flexibility
Cons
- Iron keels require corrosion vigilance
- Original low-horsepower diesel installations are aged and commonly replaced
- Limited headroom at about 5' 10" maximum
