The Rustler 31 is modestly canvassed and unhurried, with a gentle bluewater motion.
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 24.0′, the Rustler 31 tops out around 6.6 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √24.0′ 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.
SA / Displacement
12.9
Modestly canvassed — a comfortable, unhurried cruiser.
Displacement / Length
412
Heavy displacement — a slow, steady, seakindly hull.
Comfort Ratio
40.3
Very comfortable in a seaway — a genuine bluewater motion.
Capsize Screening
1.54
Below the 2.0 offshore threshold — acceptable for ocean passages.
Pounds/Inch Immersion
772lbs
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
40.3
Very comfortable in a seaway — a genuine bluewater motion.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
1.54
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 Rustler 31 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
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° |
2.3 |
2.9 |
3.3 |
3.4 |
| Close Reach60° |
2.8 |
3.5 |
3.9 |
4.1 |
| Beam Reach90° |
3.4 |
4.3 |
4.8 |
5.0 |
| Broad Reach120–135° |
3.2 |
4.0 |
4.5 |
4.7 |
| Run150–180° |
2.5 |
3.2 |
3.6 |
3.7 |
These are simplified estimates based on hull speed (6.6 kts),
SA/D (12.9), 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 Rustler 31 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–8 kts
8–22 kts
22–30 kts
30+ kts
Ghosting
0–8 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
8–22 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
22–30 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
30+ 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 Rustler 31.
|
Rustler 31 |
Cape Dory 31 |
Elvstrom 32 |
Golden Hind 31 |
Long Island 32 |
Sadler 32 |
| Dimensions |
| LOA |
31.4 |
31.3 |
31.4 |
31.5 |
31.5 |
31.5 |
| LWL |
24.0 |
23.3 |
23.5 |
26.8 |
21.5 |
24.0 |
| Beam |
9.0 |
9.8 |
10.3 |
9.0 |
10.0 |
10.5 |
| Displacement |
12 |
11 |
7 |
11 |
11 |
9 |
| Ballast |
— |
4 |
3 |
4 |
— |
4 |
| Sail Area |
440 |
504 |
345 |
409 |
414 |
423 |
| Performance |
| PHRF |
— |
198 |
— |
— |
— |
— |
| SA/Disp |
12.9 |
15.9 |
15.1 |
12.8 |
13.4 |
15.1 |
| Bal/Disp |
— |
37.8 |
44.1 |
35.3 |
— |
44.2 |
| Comfort |
40.3 |
33.3 |
18.8 |
34.1 |
32.3 |
24.4 |
| Capsize |
1.54 |
1.73 |
2.15 |
1.59 |
1.80 |
1.99 |
| Hull Speed |
6.6 |
6.5 |
6.5 |
6.9 |
6.2 |
6.6 |