Delta 31
Albin Marine · designed by Peter Norlin · 1983
fin keelBermuda rigSweden
The Delta 31 is a 31-foot bermuda rig sailboat designed by Peter Norlin and built by Albin Marine, first launched in 1983.
General
| Builder | Albin Marine |
|---|---|
| Designer | Peter Norlin |
| Years built | 1983 |
| Hull type | fin keel |
| Rig type | Bermuda rig |
| Construction | — |
| Origin | Sweden |
Dimensions
| LOA | 30.68 ft9.35 m |
|---|---|
| LWL | 24.93 ft7.60 m |
| Beam | 9.97 ft3.04 m |
| Draft (max) | 5.90 ft1.80 m |
| Displacement | 8,598 lb3,900 kg |
| Ballast | 3,505 lb1,590 kg |
| Sail Area | 436 ft²40.5 m² |
Design ratios
Computed from the specs above using the standard formulas. Try the sailboat calculators with your own numbers.
SA / Displacement 16.62 Cruiser — good all-round performance
Ballast / Displacement 40.8 % Higher = stiffer / more sail-carrying power
Displacement / Length 248 Moderate
Comfort Ratio 23.3 Coastal cruiser
Capsize Screening 1.95 Suited to offshore passages (≤ 2.0)
Hull Speed 6.7 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
$27,000 typical range $21,500 – $32,500
⚠ 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.
