Hull Speed
The theoretical displacement-mode speed limit — determined by waterline length, not engine or sail power.
5.4 kts
A displacement hull pushes a bow wave whose speed is limited by the waterline length.
With a waterline of 16.3′, the Swift 18 tops out around 5.4 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √16.3′ 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.
Displacement / Length
149
Ultralight — responsive and fast, but carries less stores.
Hull Speed
5.4kts
Pounds/Inch Immersion
3lbs
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 Swift 18.
| Swift 18 | Capri 18 Catalina | Gloucester 18 | Laguna 18 | S2 55 | Starwind 18 | |
|---|---|---|---|---|---|---|
| Dimensions | ||||||
| LOA | 18.0 | 18.0 | 18.0 | 18.0 | 18.0 | 18.0 |
| LWL | 16.3 | 16.3 | 16.7 | 14.7 | 16.3 | 16.7 |
| Beam | 7.9 | 7.6 | 6.0 | 8.0 | 7.7 | 6.0 |
| Displacement | 1 | 1 | 500 | 1 | 600 | 500 |
| Ballast | — | 425 | — | 500 | — | — |
| Sail Area | — | 155 | 175 | 151 | 176 | — |
| Performance | ||||||
| SA/Disp | — | 19.0 | 44.5 | 18.5 | 39.6 | — |
| Bal/Disp | — | 28.3 | — | — | — | — |
| Comfort | — | 9.3 | 4.2 | 9.3 | 3.7 | 4.2 |
| Capsize | — | 2.65 | 3.03 | 2.80 | 3.64 | 3.03 |
| Hull Speed | — | 5.4 | 5.5 | 5.1 | 5.4 | 5.5 |