Grampian 28
Grampian Marine · designed by Rolf van der Sleen · 1975
fin keelMasthead sloopCanada
The Grampian 28 is a 28-foot masthead sloop sailboat designed by Rolf van der Sleen and built by Grampian Marine, first launched in 1975.
General
| Builder | Grampian Marine |
|---|---|
| Designer | Rolf van der Sleen |
| Years built | 1975 |
| Hull type | fin keel |
| Rig type | Masthead sloop |
| Construction | fiberglass |
| Origin | Canada |
Dimensions
| LOA | 28.00 ft8.53 m |
|---|---|
| LWL | 24.50 ft7.47 m |
| Beam | 9.50 ft2.90 m |
| Draft (max) | 4.83 ft1.47 m |
| Displacement | 6,900 lb3,130 kg |
| Ballast | 3,060 lb1,388 kg |
| Sail Area | 384 ft²35.7 m² |
Design ratios
Computed from the specs above using the standard formulas. Try the sailboat calculators with your own numbers.
SA / Displacement 16.95 Cruiser — good all-round performance
Ballast / Displacement 44.3 % Higher = stiffer / more sail-carrying power
Displacement / Length 209 Moderate
Comfort Ratio 20.8 Coastal cruiser
Capsize Screening 2.00 Suited to offshore passages (≤ 2.0)
Hull Speed 6.6 kn Theoretical max displacement speed
How these numbers are calculated
- SA / Displacement
SA ÷ (Disp ÷ 64)^(2/3)— Power-to-weight. < 16 under-canvassed, 16–20 cruiser, > 20 racer.- Ballast / Displacement
Ballast ÷ Disp × 100— Stability/stiffness. Higher carries sail better.- Displacement / Length
Disp(lt) ÷ (0.01 · LWL)³— < 100 ultralight, 100–200 light, 200–300 moderate, > 300 heavy.- Comfort Ratio (Brewer)
Disp ÷ (0.65 · (0.7·LWL + 0.3·LOA) · Beam^1.33)— Motion in a seaway. Higher = more comfortable offshore.- Capsize Screening
Beam ÷ (Disp ÷ 64)^(1/3)— ≤ 2.0 favored for offshore; > 2.0 better for coastal use.- Hull Speed
1.34 · √LWL— Theoretical max displacement speed in knots.
Estimated price
$21,000 typical range $17,000 – $25,000
⚠ Rough estimate only — not market data. Derived from a simple model based on length and hull age; actual asking prices vary widely with condition, equipment, engine hours and location.
