The Hermann Cat 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 16.4′, the Hermann Cat tops out around 5.4 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √16.4′ LWL = 5.4 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
19.4
Powerful cruiser/racer — quick in light air, reef early when it pipes up.
Ballast / Displacement
17.9%
Light ballast — tends to be tender; reef earlier than the numbers suggest.
Displacement / Length
282
Moderate-heavy — carries provisions well, deliberate in light air.
Comfort Ratio
16.6
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
2.25
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Pounds/Inch Immersion
465lbs
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
16.6
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
2.25
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 Hermann Cat sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
Menger Cat 17
351s/nm
Cornish Shrimper 17
390s/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° |
2.3 |
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 (5.4 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 Hermann Cat — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–6 kts
6–16 kts
16–24 kts
24+ kts
Ghosting
0–6 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
6–16 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
16–24 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
24+ 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 Hermann Cat.
|
Hermann Cat |
Cape Cod Cat |
Com-Pac Sun Cat |
Cornish Shrimper 17 |
Menger Cat 17 |
Tiger Cat |
| Dimensions |
| LOA |
17.0 |
17.0 |
17.0 |
17.0 |
17.0 |
17.0 |
| LWL |
16.4 |
16.4 |
15.0 |
16.0 |
16.5 |
15.8 |
| Beam |
7.9 |
7.9 |
7.5 |
6.8 |
8.0 |
8.0 |
| Displacement |
2 |
2 |
1 |
1 |
2 |
585 |
| Ballast |
500 |
500 |
650 |
— |
500 |
— |
| Sail Area |
240 |
250 |
162 |
178 |
— |
— |
| Performance |
| PHRF |
— |
— |
— |
390 |
351 |
— |
| SA/Disp |
19.4 |
23.7 |
16.6 |
22.3 |
— |
— |
| Bal/Disp |
17.9 |
— |
33.3 |
— |
22.7 |
— |
| Comfort |
16.6 |
13.0 |
13.1 |
10.8 |
— |
3.5 |
| Capsize |
2.25 |
2.44 |
2.40 |
2.39 |
— |
3.81 |
| Hull Speed |
5.4 |
5.4 |
5.2 |
5.4 |
— |
5.3 |