Published Specification for the Jeanneau Sunfast 37
Underwater Profile: Bulb fin keel & spade rudder
Hull Material: GRP (Fibreglass)
Length Overall: 37'5" (11.4m)
Waterline Length: 31'6" (9.6m)
Beam: 12'2" (3.7m)
Draft: 6'9" (2.1m)
Rig Type: Fractional sloop
Displacement: 13,779lb (6,250kg)
Designer: Jacques Fauroux
Builder: Jeanneau (France)
Published Design Ratios for the Jeanneau Sunfast 37
1. Sail Area/Displacement Ratio: 17.8
- Less than 16 would be considered under-powered;
- 16 to 20 would indicate reasonably good performance;
- Over 20 suggests relatively high performance.
2. Ballast/Displacement Ratio: 32.6
- Under 40: less stiff, less powerful
- Over 40: stiffer, more powerful
3. Displacement/Length Ratio: 196
- Under 100: Ultralight
- 100 to 200: Light
- 200 to 275: Moderate
- 275 to 350: Heavy
- Over 350: Ultraheavy
4. Comfort Ratio: 23.0
- Under 20 indicates a lightweight racing boat
- 20 to 30 indicates a coastal cruiser
- 30 to 40 indicates a moderate offshore cruising boat
- 40 to 50 indicates a heavy offshore boat
- Over 50 indicates an extremely heavy offshore boat
5. Capsize Screening Formula: 2.0
- Under 2.0 (the lower the better): Better suited for ocean passages
- Over 2.0: Less suited for ocean passages
read more about these Key Performance Indicators...
Summary Analysis of the Design Ratios for the Jeanneau Sunfast 37
1. A Sail Area/Displacement Ratio of 17.8 suggests that the Jeanneau Sunfast 37 will, in the right conditions, approach her maximum hull speed readily and satisfy the sailing performance expectations of most cruising sailors.
2. A Ballast/Displacement Ratio of 32.6 would usually mean that the Jeanneau Sunfast 37 would have a tendency to heel uncomfortably in a gust, and need to be reefed early to keep her sailing upright in a moderate breeze.
However, as she has much of her ballast concentrated in a bulb at the foot of her keel, she's likely to be considerably stiffer than her published Ballast/Displacement Ratio might suggest.
3. A Displacement/Length Ratio of 196, tells us the Jeanneau Sunfast 37 is a light-to-moderate displacement sailboat. If she's loaded with too much heavy cruising gear her performance will suffer to a degree.
4. Ted Brewer's Comfort Ratio of 23.0 suggests that crew comfort of a Jeanneau Sunfast 37 in a seaway is similar to what you would associate with the motion of a coastal cruiser with moderate stability, which is not encouraging news for anyone prone to seasickness.
5. The Capsize Screening Formula of 2.0 tells us that a Jeanneau Sunfast 37 would not be as good a choice of sailboat for ocean passage-making, owing to the increased risk of capsize in strong winds and heavy seas, when compared to a sailboat with a CSF of less than 2.0.