The Nicholson 31 is moderately powered for comfortable coastal cruising, with a steady, comfortable ride offshore, designed for cruising comfort rather than racing.
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 24.2′, the Nicholson 31 tops out around 6.6 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √24.2′ LWL = 6.6 kts
Performance Ratios
Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.
PHRF Rating
194s/nm
Typical cruiser — designed for comfort and ease, not podium finishes.
SA / Displacement
14.1
Moderate sail power — a capable coastal cruiser, not overpowered.
Comfort Ratio
35.0
Good offshore comfort — steady enough for multi-day passages.
Capsize Screening
1.74
Below the 2.0 offshore threshold — acceptable for ocean passages.
Pounds/Inch Immersion
881lbs
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
35.0
Good offshore comfort — steady enough for multi-day passages.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
1.74
Below the 2.0 offshore threshold — acceptable for ocean passages.
Under 2.0 — Acceptable for offshore
Over 2.0 — Coastal / protected waters
PHRF Fleet Position
Where the Nicholson 31 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
Tanzer 31
165s/nm
Cape Dory 30 Mk Ii
192s/nm
Nicholson 31
194s/nm
Typical cruiser — designed for comfort and ease, not podium finishes.
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° |
2.4 |
3.0 |
3.4 |
3.5 |
| Close Reach60° |
2.9 |
3.7 |
4.1 |
4.3 |
| Beam Reach90° |
3.6 |
4.5 |
5.0 |
5.3 |
| Broad Reach120–135° |
3.3 |
4.2 |
4.7 |
4.9 |
| Run150–180° |
2.6 |
3.3 |
3.7 |
3.9 |
These are simplified estimates based on hull speed (6.6 kts),
SA/D (14.1), 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 Nicholson 31 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–7 kts
7–20 kts
20–28 kts
28+ kts
Ghosting
0–7 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
7–20 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
20–28 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
28+ 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 Nicholson 31.
|
Nicholson 31 |
Cape Dory 30 Mk Ii |
Sabre 30 3 |
Seawind Allied |
Tanzer 31 |
| Dimensions |
| LOA |
30.5 |
30.5 |
30.6 |
30.5 |
30.6 |
| LWL |
24.2 |
24.2 |
25.5 |
24.0 |
25.0 |
| Beam |
10.2 |
10.5 |
10.5 |
9.3 |
10.5 |
| Displacement |
13 |
10 |
9 |
12 |
8 |
| Ballast |
4 |
4 |
3 |
4 |
3 |
| Sail Area |
484 |
495 |
461 |
502 |
468 |
| Performance |
| PHRF |
194 |
192 |
— |
— |
165 |
| SA/Disp |
14.1 |
16.6 |
16.6 |
15.4 |
18.3 |
| Bal/Disp |
— |
40.0 |
— |
35.0 |
39.8 |
| Comfort |
35.0 |
27.2 |
23.5 |
36.9 |
21.0 |
| Capsize |
1.74 |
1.92 |
1.99 |
1.62 |
2.08 |
| Hull Speed |
6.6 |
6.6 |
6.8 |
6.6 |
6.7 |