Hull Speed
The theoretical displacement-mode speed limit — determined by waterline length, not engine or sail power.
10.4 kts
A displacement hull pushes a bow wave whose speed is limited by the waterline length.
With a waterline of 60.1′, the Oyster 675 tops out around 10.4 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √60.1′ 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.
Displacement / Length
170
Moderate — a good balance of speed and load-carrying ability.
Hull Speed
10.4kts
Pounds/Inch Immersion
24lbs
Weight needed to sink the hull one inch — loading sensitivity.
How It Compares
Side-by-side with the boats most often cross-shopped against the Oyster 675.
| Oyster 675 | Cnb 66 | Hallberg Rassy 69 | Oyster 595 | Oyster 745 | Swan 70 | |
|---|---|---|---|---|---|---|
| Dimensions | ||||||
| LOA | 69.1 | 67.6 | 72.9 | 62.5 | 74.6 | 70.1 |
| LWL | 60.1 | 60.5 | 64.6 | 55.2 | 65.7 | 61.7 |
| Beam | 18.5 | 18.1 | 19.3 | 17.6 | 19.4 | 17.5 |
| Displacement | 82 | 68 | 102 | 67 | 118 | 66 |
| Ballast | — | 20 | 39 | — | — | 23 |
| Sail Area | — | 2 | 2 | — | 3 | 2 |
| Performance | ||||||
| SA/Disp | — | 22.2 | 17.7 | — | 19.9 | 24.6 |
| Bal/Disp | — | 30.1 | 38.9 | — | — | 36.2 |
| Comfort | — | 35.9 | 45.8 | — | 51.9 | 35.2 |
| Capsize | — | 1.77 | 1.66 | — | 1.58 | 1.74 |
| Hull Speed | — | 10.4 | 10.8 | — | 10.9 | 10.5 |