The Jeanneau Sunfast 37 Sailboat
Specs & Key Performance Indicators

The Jeanneau Sunfast 37, an aft-cockpit sloop, was designed by Jacques Fauroux and built in France by Jeanneau.

A Jeanneau Sunfast 37

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

Summary Analysis of the Design Ratios for the Jeanneau Sunfast 37

eBook: How to Avoid Buying the Wrong Sailboat

Download this eBook to make sure you buy wisely!

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.