The Sud 25 is well-powered with enough sail area to move in light air, with a quick, snappy motion best suited to day sailing.
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 21.0′, the Sud 25 tops out around 6.1 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √21.0′ LWL = 6.1 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
21.5
Powerful cruiser/racer — quick in light air, reef early when it pipes up.
Ballast / Displacement
46.9%
Race-oriented ballast ratio — very stiff and powerful.
Displacement / Length
186
Moderate — a good balance of speed and load-carrying ability.
Comfort Ratio
15.0
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
2.26
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Pounds/Inch Immersion
665lbs
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
15.0
Quick, snappy motion — better for day sails and racing than long passages.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
2.26
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Under 2.0 — Acceptable for offshore
Over 2.0 — Coastal / protected waters
PHRF Fleet Position
Where the Sud 25 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser 150–210
Heavy Cruiser 210–300
Ranger 23
222s/nm
Pearson 24
252s/nm
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° |
2.8 |
3.5 |
3.9 |
4.1 |
| Close Reach60° |
3.3 |
4.2 |
4.7 |
4.9 |
| Beam Reach90° |
4.1 |
5.2 |
5.8 |
6.3 |
| Broad Reach120–135° |
3.8 |
4.8 |
5.3 |
5.8 |
| Run150–180° |
3.0 |
3.8 |
4.3 |
4.5 |
These are simplified estimates based on hull speed (6.1 kts),
SA/D (21.5), 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 Sud 25 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–6 kts
6–20 kts
20–30 kts
30+ kts
Ghosting
0–6 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
6–20 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
20–30 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
30+ 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 Sud 25.
|
Sud 25 |
Achilles 24 |
Hunter 235 |
Jouet 24 |
Pearson 24 |
Ranger 23 |
| Dimensions |
| LOA |
23.6 |
23.8 |
23.5 |
23.6 |
23.5 |
23.7 |
| LWL |
21.0 |
19.5 |
20.5 |
21.0 |
18.5 |
20.0 |
| Beam |
8.9 |
7.1 |
8.3 |
8.9 |
8.0 |
7.9 |
| Displacement |
3 |
2 |
3 |
3 |
4 |
3 |
| Ballast |
1 |
1 |
1 |
1 |
1 |
1 |
| Sail Area |
330 |
210 |
250 |
338 |
— |
244 |
| Performance |
| PHRF |
— |
— |
— |
— |
252 |
222 |
| SA/Disp |
21.5 |
17.8 |
16.4 |
22.1 |
— |
17.3 |
| Bal/Disp |
46.9 |
50.5 |
39.5 |
— |
41.9 |
— |
| Comfort |
15.0 |
14.2 |
— |
15.0 |
— |
15.8 |
| Capsize |
2.26 |
2.06 |
— |
2.26 |
— |
2.11 |
| Hull Speed |
6.1 |
5.9 |
— |
6.1 |
— |
6.0 |