The Bristol 40 Sailboat
Specs & Key Performance Indicators

Published Specification for the Bristol 40

Underwater Profile: Long keel

Hull Material: GRP (Fibreglass)

Length Overall: 40'2" (12.2m)

Waterline Length: 27'6" (8.4m)

Beam: 10'9" (3.3m)

Draft: 5'4" (1.6m)

Rig Type: Masthead sloop (also available as a yawl or cutter)

Displacement: 17,580lb (7,974kg)

Ballast: 6,500lb (2,948kg)

Designer: Ted Hood

Builder: Bristol Yachts (USA)

Year First Built: 1970

Year Last Built: 1986

Number Built: 149

Published Design Ratios for the Bristol 40

1. Sail Area/Displacement Ratio: 16.5

• 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: 37.0

• Under 40: less stiff, less powerful
• Over 40: stiffer, more powerful

3. Displacement/Length Ratio: 376

• Under 100: Ultralight
• 100 to 200: Light
• 200 to 275: Moderate
• 275 to 350: Heavy
• Over 350: Ultraheavy

4. Comfort Ratio: 36.7

• 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: 1.7

• 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 Bristol 40

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1. A Sail Area/Displacement Ratio of 16.5 suggests that the Bristol 40 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 37.0 means that a sailboat like the Bristol 40, is likely to benefit from being reefed early to keep her sailing upright in a moderate breeze.

3. A Displacement/Length Ratio of 376 tells us the Bristol 40 is firmly in the ultra-heavy displacement category. Load her up as much as you like and her performance will be hardly affected, not that it was ever startling. Few if any sailboats are built to this displacement category these days - but they remain popular with some long-distance sailors.

4. Ted Brewer's Comfort Ratio of 36.7 suggests that crew comfort of a Bristol 40 in a seaway is similar to what you would associate with the motion of a moderate bluewater cruising boat - a predictable and acceptable motion for most seasoned sailors.

5. The Capsize Screening Formula (CSF) of 1.7 indicates that a Bristol 40 would be a safer choice of sailboat for an ocean passage than one with a CSF of more than 2.0.