The Dufour 40 is well-powered with enough sail area to move in light air, with acceptable motion comfort for coastal passages, and respectable in club racing.
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 35.2′, the Dufour 40 tops out around 8.0 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √35.2′ LWL = 8.0 kts
Performance Ratios
Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.
PHRF Rating
96s/nm
Cruiser/racer — competitive in club racing, comfortable cruising.
SA / Displacement
20.9
Powerful cruiser/racer — quick in light air, reef early when it pipes up.
Ballast / Displacement
36.1%
Typical cruising ballast — balanced stability and motion underway.
Displacement / Length
175
Moderate — a good balance of speed and load-carrying ability.
Comfort Ratio
24.2
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Capsize Screening
1.99
Below the 2.0 offshore threshold — acceptable for ocean passages.
SA/Disp (Calculated)
17.7
Computed from measured I/J/P/E rather than reported sail area.
Pounds/Inch Immersion
1lbs
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
24.2
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
1.99
Below the 2.0 offshore threshold — acceptable for ocean passages.
Under 2.0 — Acceptable for offshore
Over 2.0 — Coastal / protected waters
PHRF Fleet Position
Where the Dufour 40 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Cruiser 150–210
Dufour 40
96s/nm
Cruiser/racer — competitive in club racing, comfortable cruising.
Catalina 400
102s/nm
Bavaria 40 Jj
108s/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° |
3.5 |
4.4 |
5.0 |
5.2 |
| Close Reach60° |
4.3 |
5.4 |
6.0 |
6.3 |
| Beam Reach90° |
5.2 |
6.6 |
7.4 |
8.0 |
| Broad Reach120–135° |
4.8 |
6.1 |
6.8 |
7.4 |
| Run150–180° |
3.9 |
4.9 |
5.4 |
5.7 |
These are simplified estimates based on hull speed (8.0 kts),
SA/D (20.9), 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 Dufour 40 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–6 kts
6–18 kts
18–26 kts
26+ kts
Ghosting
0–6 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
6–18 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
18–26 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
26+ 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 Dufour 40.
|
Dufour 40 |
Bavaria 40 Jj |
Catalina 400 |
Hunter 405 Legend |
Oceanis 400 Beneteau |
Sun Fast 40 Jeanneau |
| Dimensions |
| LOA |
40.4 |
40.4 |
40.5 |
40.5 |
40.4 |
40.4 |
| LWL |
35.2 |
34.5 |
34.8 |
34.8 |
34.5 |
34.5 |
| Beam |
12.8 |
13.5 |
13.5 |
13.7 |
13.5 |
13.1 |
| Displacement |
17 |
19 |
18 |
19 |
19 |
14 |
| Ballast |
6 |
7 |
7 |
7 |
6 |
5 |
| Sail Area |
866 |
790 |
808 |
780 |
754 |
861 |
| Performance |
| PHRF |
96 |
108 |
102 |
— |
— |
— |
| SA/Disp |
20.9 |
17.2 |
18.9 |
17.5 |
16.7 |
22.8 |
| Bal/Disp |
36.1 |
35.6 |
40.0 |
40.0 |
35.2 |
40.3 |
| Comfort |
24.2 |
23.7 |
23.8 |
24.5 |
25.8 |
20.3 |
| Capsize |
1.99 |
2.01 |
2.06 |
2.05 |
2.01 |
2.14 |
| Hull Speed |
8.0 |
8.0 |
7.9 |
7.9 |
7.9 |
7.9 |