The Thom Cat 19 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 18.4′, the Thom Cat 19 tops out around 5.8 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √18.4′ LWL = 5.8 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
21.3
Powerful cruiser/racer — quick in light air, reef early when it pipes up.
Comfort Ratio
15.1
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
527lbs
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
15.1
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 Thom Cat 19 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser 150–210
Heavy Cruiser 210–300
Rhodes 19
261s/nm
Menger Cat 19
326s/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 |
3.2 |
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 (5.8 kts),
SA/D (21.3), 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 Thom Cat 19 — 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 Thom Cat 19.
|
Thom Cat 19 |
Alerion Express 19 |
Com Pac 19 |
Cornish Coble |
Menger Cat 19 |
Rhodes 19 |
| Dimensions |
| LOA |
19.0 |
19.2 |
19.0 |
19.0 |
19.0 |
19.2 |
| LWL |
18.4 |
18.9 |
16.3 |
13.3 |
18.4 |
17.8 |
| Beam |
8.0 |
8.7 |
7.0 |
6.0 |
8.0 |
7.0 |
| Displacement |
2 |
1 |
2 |
599 |
2 |
1 |
| Ballast |
600 |
300 |
800 |
— |
600 |
415 |
| Sail Area |
270 |
— |
145 |
131 |
— |
175 |
| Performance |
| PHRF |
— |
— |
— |
— |
326 |
261 |
| SA/Disp |
21.3 |
— |
14.7 |
29.5 |
— |
22.9 |
| Bal/Disp |
— |
17.1 |
40.0 |
— |
20.7 |
— |
| Comfort |
15.1 |
8.0 |
13.5 |
5.7 |
— |
8.6 |
| Capsize |
2.25 |
2.88 |
2.22 |
2.85 |
— |
2.53 |
| Hull Speed |
5.8 |
5.8 |
5.4 |
4.9 |
— |
5.7 |