The Duncanson 25 is well-powered with enough sail area to move in light air, with a quick, snappy motion best suited to day sailing.
Hull Speed
The theoretical displacement-mode speed limit — determined by waterline length, not engine or sail power.
A displacement hull pushes a bow wave whose speed is limited by the waterline length.
With a waterline of 22.6′, the Duncanson 25 tops out around 6.4 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √22.6′ LWL = 6.4 kts
Performance Ratios
Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.
SA / Displacement
18.5
Powerful cruiser/racer — quick in light air, reef early when it pipes up.
Ballast / Displacement
35.8%
Typical cruising ballast — balanced stability and motion underway.
Displacement / Length
130
Ultralight — responsive and fast, but carries less stores.
Comfort Ratio
13.9
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
2.14
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Pounds/Inch Immersion
4lbs
Weight needed to sink the hull one inch — loading sensitivity.
Motion & Offshore Suitability
Two ratios that matter most when you're planning passages — how the boat feels in a seaway, and whether the hull geometry is suitable for open ocean.
Comfort Ratio
13.9
Quick, snappy motion — better for day sails and racing than long passages.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
2.14
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Under 2.0 — Acceptable for offshore
Over 2.0 — Coastal / protected waters
PHRF Fleet Position
Where the Duncanson 25 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
Albin Express
174s/nm
Ericson 25 1
234s/nm
Estimated Speed by Wind
Rough boat speed estimates at different true wind speeds and points of sail — derived from hull speed, SA/D, and displacement, not measured polars.
| Point of Sail |
6 kts TWS |
10 kts TWS |
15 kts TWS |
20 kts TWS |
| Close-hauled40–50° |
2.6 |
3.3 |
3.7 |
3.9 |
| Close Reach60° |
3.2 |
4.0 |
4.5 |
4.7 |
| Beam Reach90° |
3.9 |
5.0 |
5.5 |
6.0 |
| Broad Reach120–135° |
3.6 |
4.6 |
5.1 |
5.5 |
| Run150–180° |
2.9 |
3.7 |
4.1 |
4.3 |
These are simplified estimates based on hull speed (6.4 kts),
SA/D (18.5), and empirical efficiency curves — not instrument-measured
polars. Real-world speed varies with sea state, bottom condition, sail trim, and current.
Speeds in gold approach hull speed;
bold gold means near or at hull speed.
Wind Range & Comfort Envelope
Estimated wind ranges for comfortable sailing on the Duncanson 25 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–6 kts
6–18 kts
18–26 kts
26+ kts
Ghosting
0–6 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
6–18 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
18–26 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
26+ kts
Storm conditions. Storm jib or bare poles. Seek shelter if coastal.
How It Compares
Side-by-side with the boats most often cross-shopped against the Duncanson 25.
|
Duncanson 25 |
Albin Express |
Ericson 25 1 |
Evelyn 255 |
First Class 8 Beneteau |
Hunter 255 |
| Dimensions |
| LOA |
25.5 |
25.5 |
25.4 |
25.5 |
25.4 |
25.6 |
| LWL |
22.6 |
21.6 |
21.8 |
22.3 |
21.7 |
22.1 |
| Beam |
8.0 |
8.2 |
9.3 |
9.0 |
8.2 |
9.1 |
| Displacement |
3 |
3 |
5 |
4 |
3 |
4 |
| Ballast |
1 |
1 |
2 |
1 |
1 |
1 |
| Sail Area |
258 |
317 |
325 |
326 |
316 |
282 |
| Performance |
| PHRF |
— |
174 |
234 |
— |
— |
— |
| SA/Disp |
18.5 |
20.3 |
17.8 |
20.1 |
23.8 |
16.6 |
| Bal/Disp |
35.8 |
44.5 |
40.0 |
33.3 |
37.1 |
40.0 |
| Comfort |
13.9 |
16.3 |
17.4 |
15.0 |
12.8 |
15.9 |
| Capsize |
2.14 |
2.07 |
2.17 |
2.23 |
2.24 |
2.20 |
| Hull Speed |
6.4 |
6.2 |
6.3 |
6.3 |
6.2 |
6.3 |