Hull Form and Stability
The Dufour 41 carries a fin keel with the rudder mounted on a skeg "fin keel rudder on skeg"), a configuration that balances upwind performance with directional security. The keel carries 7,800 pounds of ballast against a displacement of 19,400 pounds "ballast and displacement figures"), producing a ballast-to-displacement ratio of 40.21 "ballast displacement ratio"). Per the sailboatdata formula definitions, a ratio of 40 or more translates into a stiffer, more powerful boat that will be better able to stand up to the wind. The capsize screening formula comes in at 1.84 "capsize screening value"), comfortably below the 2.0 threshold for offshore suitability, indicating the hull geometry is not prone to capsize vulnerability in steep breaking seas.
Rig and Sail Power
The standard configuration is a masthead sloop "masthead sloop rigging"), though the design was also available as a ketch "available as sloop or ketch"), offering owners a choice between a single-stick rig and the divided canvas of a two-masted arrangement. The reported sail area of 685 square feet "685 square feet sail area") yields a sail-area-to-displacement ratio of 15.24 "SA displacement ratio"). A ratio below 16 is considered underpowered by conventional cruising standards, placing the Dufour 41 at the lower boundary of adequate drive. The theoretical hull speed of 7.58 knots "theoretical hull speed") reflects a waterline length that is generous for a boat of this era.
Motion Comfort and Offshore Character
With a displacement-to-length ratio of 264 "displacement length ratio"), the Dufour 41 sits in the moderate category — heavier than a coastal racer, lighter than a traditional passagemaker. The comfort ratio of 30.45 "Ted Brewer comfort ratio"), calculated using Ted Brewer's formula, places the hull at the lower boundary of the moderate bluewater cruising range (30–40), meaning offshore motion is manageable and suited to extended passages.
Tankage and Auxiliary Power
The original auxiliary fit was a Perkins 4-107 diesel producing 41 horsepower "Perkins 4-107 diesel engine"). Fuel capacity was 65 gallons "65-gallon fuel tank"), and fresh water stowage reaches 78 gallons "78-gallon water tank") — figures that support extended passages without constant reprovisioning.
The Verdict
The Dufour 41 is a competent, moderate-displacement French cruiser that holds its own against contemporaries of similar size. The Michel Dufour design pedigree "Michel Dufour designer credit") brought offshore thinking to a production hull, and the conservative stability numbers — particularly the ballast ratio and capsize screening formula — confirm that the hull was engineered with bluewater conditions in mind. Where it asks for patience is in light-air performance; the sail-area ratio falls below 16, the conventional threshold for adequate power.
Pros
- Ballast-to-displacement ratio at 40 delivers genuine stiffness under sail
- Capsize screening figure well below the offshore threshold
- Generous fuel and water tankage for extended passages
- Masthead or ketch rig options give owners flexibility for their sailing program
Cons
- Sail-area-to-displacement ratio below 16 means limited drive in light winds
- Comfort ratio at the lower boundary of the moderate bluewater range — motion is manageable but not exceptional
- Fin-and-skeg configuration, while capable, suits those who prefer active sailing over passive tracking
