The S Class Herreshoff is well-powered with enough sail area to move in light air, with a steady, comfortable ride offshore.
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 20.5′, the S Class Herreshoff tops out around 6.1 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √20.5′ LWL = 6.1 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
19.4
Powerful cruiser/racer — quick in light air, reef early when it pipes up.
Ballast / Displacement
49.6%
Race-oriented ballast ratio — very stiff and powerful.
Displacement / Length
350
Moderate-heavy — carries provisions well, deliberate in light air.
Comfort Ratio
33.5
Good offshore comfort — steady enough for multi-day passages.
Capsize Screening
1.52
Below the 2.0 offshore threshold — acceptable for ocean passages.
Pounds/Inch Immersion
525lbs
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
33.5
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
1.52
Below the 2.0 offshore threshold — acceptable for ocean passages.
Under 2.0 — Acceptable for offshore
Over 2.0 — Coastal / protected waters
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 |
3.6 |
3.8 |
| Close Reach60° |
3.1 |
3.9 |
4.4 |
4.6 |
| Beam Reach90° |
3.8 |
4.8 |
5.4 |
5.6 |
| Broad Reach120–135° |
3.5 |
4.5 |
5.0 |
5.2 |
| Run150–180° |
2.8 |
3.6 |
4.0 |
4.2 |
These are simplified estimates based on hull speed (6.1 kts),
SA/D (19.4), 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 S Class Herreshoff — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–6 kts
6–20 kts
20–30 kts
30+ kts
Ghosting
0–6 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
6–20 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
20–30 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 S Class Herreshoff.
|
S Class Herreshoff |
Contessa 27 |
Controversy 27 |
Eastern Yacht Club 17 |
Honey Bee 28 |
Northeast Harbor A Class |
| Dimensions |
| LOA |
27.5 |
27.5 |
27.5 |
27.5 |
27.5 |
27.5 |
| LWL |
20.5 |
23.5 |
22.5 |
17.0 |
21.0 |
17.0 |
| Beam |
7.2 |
10.0 |
7.9 |
7.3 |
8.0 |
7.3 |
| Displacement |
6 |
5 |
4 |
3 |
9 |
3 |
| Ballast |
3 |
2 |
— |
— |
3 |
— |
| Sail Area |
431 |
413 |
316 |
368 |
305 |
368 |
| Performance |
| SA/Disp |
19.4 |
20.7 |
18.3 |
27.8 |
10.9 |
27.8 |
| Bal/Disp |
49.6 |
45.4 |
— |
— |
32.6 |
— |
| Comfort |
33.5 |
16.8 |
18.8 |
17.0 |
40.2 |
17.0 |
| Capsize |
1.52 |
2.24 |
1.91 |
1.99 |
1.51 |
1.99 |
| Hull Speed |
6.1 |
6.5 |
6.4 |
5.5 |
6.1 |
5.5 |