Hull Speed
The theoretical displacement-mode speed limit — determined by waterline length, not engine or sail power.
4.7 kts
A displacement hull pushes a bow wave whose speed is limited by the waterline length.
With a waterline of 12.3′, the Marlin 18 Rhodes tops out around 4.7 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √12.3′ LWL = 4.7 kts
Performance Ratios
Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.
Ballast / Displacement
34.4%
Typical cruising ballast — balanced stability and motion underway.
Displacement / Length
304
Moderate-heavy — carries provisions well, deliberate in light air.
Hull Speed
4.7kts
Pounds/Inch Immersion
1lbs
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 Marlin 18 Rhodes.
| Marlin 18 Rhodes | Duxbury Duck | Interlake | Jollyboat | Mercury 18 | Rhodes 18 | |
|---|---|---|---|---|---|---|
| Dimensions | ||||||
| LOA | 18.1 | 18.0 | 18.0 | 18.0 | 18.0 | 18.0 |
| LWL | 12.3 | 15.1 | — | 17.5 | 13.0 | 17.0 |
| Beam | 5.3 | 6.3 | 6.3 | 5.0 | 5.3 | 6.3 |
| Displacement | 1 | 700 | 650 | 300 | 1 | 1 |
| Ballast | 430 | — | — | — | 635 | — |
| Sail Area | — | 342 | 175 | 160 | — | 162 |
| Performance | ||||||
| SA/Disp | — | 69.5 | 37.4 | 57.2 | — | 25.1 |
| Bal/Disp | 34.4 | — | — | — | 57.7 | — |
| Comfort | — | 5.8 | 5.4 | 3.1 | — | 8.2 |
| Capsize | — | 2.85 | 2.89 | 2.99 | — | 2.46 |
| Hull Speed | — | 5.2 | 5.2 | 5.6 | — | 5.5 |