The Cnb 66 is aggressively canvassed for its weight, 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 60.5′, the Cnb 66 tops out around 10.4 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √60.5′ LWL = 10.4 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
22.2
Performance-oriented — carries a lot of canvas for its weight.
Ballast / Displacement
30.1%
Typical cruising ballast — balanced stability and motion underway.
Displacement / Length
138
Ultralight — responsive and fast, but carries less stores.
Comfort Ratio
35.9
Good offshore comfort — steady enough for multi-day passages.
Capsize Screening
1.77
Below the 2.0 offshore threshold — acceptable for ocean passages.
SA/Disp (Calculated)
19.6
Computed from measured I/J/P/E rather than reported sail area.
Pounds/Inch Immersion
3lbs
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
35.9
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
1.77
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° |
4.8 |
6.0 |
6.7 |
7.0 |
| Close Reach60° |
5.8 |
7.3 |
8.1 |
8.5 |
| Beam Reach90° |
7.1 |
8.9 |
10.0 |
10.8 |
| Broad Reach120–135° |
6.5 |
8.3 |
9.2 |
10.0 |
| Run150–180° |
5.2 |
6.6 |
7.4 |
7.7 |
These are simplified estimates based on hull speed (10.4 kts),
SA/D (22.2), 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 Cnb 66 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–5 kts
5–16 kts
16–24 kts
24+ kts
Ghosting
0–5 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
5–16 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 Cnb 66.
|
Cnb 66 |
Jeanneau Yachts 65 |
Oyster 675 |
Swan 65 Frers |
Swan 66 S |
Swan 70 |
| Dimensions |
| LOA |
67.6 |
66.6 |
69.1 |
66.0 |
66.0 |
70.1 |
| LWL |
60.5 |
57.7 |
60.1 |
60.3 |
56.4 |
61.7 |
| Beam |
18.1 |
18.7 |
18.5 |
18.4 |
17.7 |
17.5 |
| Displacement |
68 |
68 |
82 |
60 |
66 |
66 |
| Ballast |
20 |
24 |
— |
14 |
20 |
23 |
| Sail Area |
2 |
2,045 |
— |
— |
2 |
2 |
| Performance |
| SA/Disp |
22.2 |
19.5 |
— |
— |
21.0 |
24.6 |
| Bal/Disp |
30.1 |
35.5 |
— |
24.1 |
31.4 |
36.2 |
| Comfort |
35.9 |
35.1 |
— |
— |
37.5 |
35.2 |
| Capsize |
1.77 |
1.83 |
— |
— |
1.75 |
1.74 |
| Hull Speed |
10.4 |
10.2 |
— |
— |
10.1 |
10.5 |