Designed as a compact and accessible small sailboat, the Thom Cat 15 falls into the category of trailerable daysailers well-suited for inland lakes, sheltered bays, and calm coastal waters. With limited specification data widely available, the Thom Cat 15 remains a somewhat obscure design, though its modest size suggests it was built with beginner-friendly sailing and casual recreational use in mind rather than competitive racing or bluewater adventure.
Boats of this class typically appeal to sailors looking for an affordable entry point into the sport or those seeking a low-maintenance vessel that can be easily trailered and launched without a large crew or elaborate infrastructure. The Thom Cat 15 likely rewards solo or two-person sailing in light to moderate conditions, making weekend outings and relaxed daysailing its natural environment.
For prospective buyers, tracking down original builder documentation or connecting with current owners through sailing forums may be the best path to uncovering detailed specifications and firsthand impressions. Despite its relative obscurity, the right buyer may find the Thom Cat 15 a charming and practical choice for simple, enjoyable time on the water.
SA/Displacement
Sail Area to Displacement ratio measures how much sail power a boat has relative to its weight. Higher values mean more performance and speed.
Under 14 — Heavy cruiser, slow14–18 — Cruising sailboat18–22 — Cruiser/racerOver 22 — Performance racer
29.47
Comfort Ratio
Ted Brewer's Comfort Ratio predicts how comfortable a boat will feel in offshore conditions. Higher values mean a steadier, more comfortable motion in a seaway.
Under 20 — Uncomfortably rough20–30 — Acceptable coastal30–40 — Good offshore comfortOver 40 — Very comfortable offshore
5.4
Capsize Screening Formula
The USHS Capsize Screening Formula estimates offshore capsize risk. Lower is safer — values under 2.0 are considered acceptable for offshore sailing.
Under 2.0 — Safe for offshore2.0–2.2 — Borderline offshoreOver 2.2 — Coastal use recommended
3.16
Hull Speed
Hull Speed is the theoretical maximum speed of a displacement hull, calculated from waterline length. Most cruising sailboats reach this speed in moderate conditions.
5.19
Pounds/Inch Immersion
Pounds per Inch Immersion (PPI) tells you how much weight is needed to sink the boat one inch. Useful for calculating how additional gear and stores affect waterline.
375.18