Hull Speed
The theoretical displacement-mode speed limit — determined by waterline length, not engine or sail power.
6.7 kts
A displacement hull pushes a bow wave whose speed is limited by the waterline length.
With a waterline of 25.0′, the Southerly 101 tops out around 6.7 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √25.0′ LWL = 6.7 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
44.3%
Stiff enough to carry a big genoa comfortably into moderate breeze.
Displacement / Length
284
Moderate-heavy — carries provisions well, deliberate in light air.
Hull Speed
6.7kts
Pounds/Inch Immersion
5lbs
Weight needed to sink the hull one inch — loading sensitivity.
PHRF Fleet Position
Where the Southerly 101 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Pearson 34
Tartan 33
How It Compares
Side-by-side with the boats most often cross-shopped against the Southerly 101.
| Southerly 101 | Hallberg Rassy 34 | Pearson 34 | Southerly 100 | Tartan 33 | |
|---|---|---|---|---|---|
| Dimensions | |||||
| LOA | 33.8 | 33.7 | 33.8 | 33.8 | 33.7 |
| LWL | 25.0 | 28.5 | 28.1 | 25.0 | 28.8 |
| Beam | 10.3 | 11.2 | 11.2 | 10.3 | 11.0 |
| Displacement | 9 | 11 | 11 | 9 | 10 |
| Ballast | 4 | 4 | 4 | 4 | 4 |
| Sail Area | — | 592 | 550 | 509 | 531 |
| Performance | |||||
| PHRF | — | — | 144 | — | 153 |
| SA/Disp | — | 18.5 | 17.6 | 17.7 | 18.4 |
| Bal/Disp | 44.3 | 39.6 | — | — | — |
| Comfort | — | 24.0 | 23.4 | 25.1 | 21.0 |
| Capsize | — | 1.98 | 2.00 | 1.91 | 2.04 |
| Hull Speed | — | 7.2 | 7.1 | 6.7 | 7.2 |