Back to Search
Discovery 79 Grampian
Designer: Alex Mcgruer  ·  Builder: Grampian Marine Ltd. (Can)  ·  First built: 1975
+ Add to Compare
About the Discovery 79 Grampian

Built during a brief three-year production run from 1975 to 1977, this 26-foot masthead sloop represents Grampian Marine's approach to affordable cruising sailboats. Designer Alex Mcgruer created a practical coastal cruiser with a moderate fin keel and transom-hung rudder configuration that balances performance with ease of handling. The fiberglass construction features sensible proportions, with a beam of 8.33 feet providing reasonable interior volume while maintaining decent sailing characteristics. At 5,100 pounds displacement with 2,300 pounds of ballast, the boat offers sufficient stability for coastal cruising and weekend adventures. The 318 square feet of sail area in a masthead sloop rig delivers adequate power for light to moderate conditions. With a comfort ratio of 20.32, this design leans toward the sportier side of the cruising spectrum, making it well-suited for day sailing and short coastal passages rather than extended offshore voyaging. The capsize screening value of 1.94 indicates reasonable stability for protected waters and moderate conditions. Like many Grampian designs of this era, the boat appeals to sailors seeking an affordable entry into cruising sailboats, offering basic accommodations and straightforward sailing characteristics that make it suitable for newer sailors developing their skills.

Core Dimensions
LOA (Length Overall) 26.00 ft / 7.92 m
LWL (Waterline Length) 21.75 ft / 6.63 m
Beam 8.33 ft / 2.54 m
Max Draft 3.75 ft / 1.14 m
Displacement 5,100.00 lb / 2,313 kg
Ballast 2,300.00 lb / 1,043 kg
Sail Area (Reported) 318.00 ft² / 29.54 m²
Design & Construction
Hull Type Fin w/transom hung rudder
Rigging Type Masthead Sloop
Construction FG
Designer Alex McGruer
Builder Grampian Marine Ltd. (CAN)
First Built 1975
Last Built 1977
Associations Grampian Owners Marina
Owner Reviews

No owner reviews yet — be the first to share your experience with this boat.

Known Issues & What to Watch For

No known issues documented for this model yet.

Own or have surveyed a Discovery 79 Grampian? Submit a known issue

Performance Ratios
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
 17.22
Ballast/Displacement Ballast to Displacement ratio shows what percentage of the boat's total weight is ballast. Higher values generally mean better initial stability and stiffer sail carrying.
30–35% — Typical cruiser35–45% — Stiff performance boatOver 45% — Racing oriented
 45.1
Displacement/Length Displacement to Length ratio measures how heavy a boat is relative to its waterline length. Lower values mean a lighter, faster boat.
Under 100 — Ultralight racer100–200 — Light cruiser/racer200–300 — Moderate cruiser300–400 — Heavy cruiserOver 400 — Very heavy
 221.28
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
 20.32
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
 1.94
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. 6.25 kn
S# (Speed Number) The Speed Number (S#) is a quick performance index. Higher values indicate a faster, more powerful design relative to its size.
Under 3.0 — Slow cruiser3.0–5.0 — Average cruiser5.0–7.0 — Performance cruiserOver 7.0 — Racer
 2.52
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. 647.37 pounds/inch
SA/Displacement (Calc) Calculated Sail Area to Displacement ratio using actual measured sail dimensions rather than reported values. More precise than the reported SA/Disp figure. 17.49
Rig Dimensions
I (Foretriangle Height) 33.25 ft / 10.13 m
J (Foretriangle Base) 11.00 ft / 3.35 m
P (Mainsail Luff) 28.00 ft / 8.53 m
E (Mainsail Foot) 10.00 ft / 3.05 m
SA Fore 182.88 ft² / 16.99 m²
SA Main 140.00 ft² / 13.01 m²
SA Total (100%) 322.88 ft² / 30.00 m²
Est. Forestay Length 35.02 ft / 10.67 m
Find a Discovery 79 Grampian For Sale
Y YachtWorld Brokerage listings S Sailboat Listings Sailboats only C Craigslist National search F Facebook Marketplace Local listings B boats.com Global marketplace