The Cooper 353 is moderately powered for comfortable coastal cruising, with acceptable motion comfort for coastal passages.
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 28.5′, the Cooper 353 tops out around 7.2 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √28.5′ LWL = 7.2 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
16.3
Moderate sail power — a capable coastal cruiser, not overpowered.
Ballast / Displacement
36.2%
Typical cruising ballast — balanced stability and motion underway.
Displacement / Length
251
Moderate-heavy — carries provisions well, deliberate in light air.
Comfort Ratio
24.1
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Capsize Screening
2.05
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Pounds/Inch Immersion
1lbs
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
24.1
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
2.05
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 Cooper 353 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Cruiser 150–210
Santana 35
120s/nm
C&C 35
126s/nm
Oday 35
149s/nm
Ct 35
198s/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° |
2.8 |
3.5 |
3.9 |
4.1 |
| Close Reach60° |
3.4 |
4.3 |
4.8 |
5.0 |
| Beam Reach90° |
4.1 |
5.2 |
5.8 |
6.1 |
| Broad Reach120–135° |
3.8 |
4.8 |
5.4 |
5.6 |
| Run150–180° |
3.1 |
3.9 |
4.3 |
4.5 |
These are simplified estimates based on hull speed (7.2 kts),
SA/D (16.3), 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 Cooper 353 — 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 Cooper 353.
|
Cooper 353 |
C&C 35 |
Ct 35 |
Oday 35 |
Santana 35 |
Young Sun 35 |
| Dimensions |
| LOA |
35.0 |
— |
35.0 |
35.0 |
35.0 |
35.0 |
| LWL |
28.5 |
— |
26.8 |
28.8 |
26.5 |
32.0 |
| Beam |
12.0 |
— |
11.2 |
11.3 |
11.9 |
11.0 |
| Displacement |
13 |
— |
16 |
11 |
8 |
19 |
| Ballast |
4 |
— |
5 |
4 |
3 |
6 |
| Sail Area |
560 |
— |
483 |
524 |
550 |
— |
| Performance |
| PHRF |
— |
126 |
198 |
149 |
120 |
— |
| SA/Disp |
16.3 |
— |
11.8 |
16.5 |
21.2 |
— |
| Bal/Disp |
36.2 |
— |
31.4 |
— |
— |
34.9 |
| Comfort |
24.1 |
— |
35.9 |
23.1 |
16.7 |
— |
| Capsize |
2.05 |
— |
1.74 |
2.00 |
2.34 |
— |
| Hull Speed |
7.2 |
— |
6.9 |
7.2 |
6.9 |
— |