The Grand Soleil 343 Sailboat
Specs & Key Performance Indicators

Published Specification for the Grand Soleil 343

Underwater Profile: Fin keel & spade rudder

Hull Material: GRP (Fibreglass)

Length Overall: 34'2" (10.4m)

Waterline Length: 28'9" (8.8m)

Beam: 11'3" (3.4m)

Draft: 5'11" (1.8m)

Rig Type: Masthead sloop

Displacement: 10,251lb (4,650kg)

Ballast: 3,858lb (1,750kg)

Designer: Alain Jezequel

Builder: Grand Soleil (Italy)

Year First Built: 1985

Published Design Ratios for the Grand Soleil 343

1. Sail Area/Displacement Ratio: 22.8

• 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: 37.6

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

3. Displacement/Length Ratio: 193

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

4. Comfort Ratio: 20.9

• 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: 2.1

• 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 Grand Soleil 343

Download this eBook to make sure you buy wisely!

1. A Sail Area/Displacement Ratio of 22.8 suggests that, in the right hands, the Grand Soleil 343 will have enough performance to leave most other sailboats of similar waterline length well astern. 

2. A Ballast/Displacement Ratio of 37.6 means that a sailboat like the Grand Soleil 343 (which doesn't have a stiffness-enhancing bulb keel), is likely to benefit from being reefed early to keep her sailing upright in a moderate breeze.

3. A Displacement/Length Ratio of 193, tells us the Grand Soleil 343 is clearly a light 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 20.9 suggests that crew comfort of a Grand Soleil 343 in a seaway is similar to what you would associate with the motion of a coastal cruiser with moderate stability, which is not the best of news for anyone prone to seasickness. 

5. The Capsize Screening Formula of 2.1 tells us that a Grand Soleil 343 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.