The J46 Sailboat
Specs & Key Performance Indicators

Published Specification for the J46

Underwater Configuration: Bulb fin keel & spade rudder

Hull Material: GRP (Fibreglass)

Length Overall: 46'0" (14.0m)

Waterline Length: 40'6" (12.3m)

Beam: 13'10" (4.2m)

Draft: 6'3" (1.9m)

Rig Type: Masthead sloop

Displacement: 24,000lb (10,886kg)

Designer: Rod Johnstone

Builder: J Boats (USA)

Year First Built: 1995

Year Last Built: 2003

Number Built: 35

Owners Association: J Boat Owners

Published Design Ratios for the J46

1. Sail Area/Displacement Ratio: 19.7

• 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: 39.2

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

3. Displacement/Length Ratio: 161

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

4. Comfort Ratio: 26.7

• 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: 1.9

• 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 J46

Download this eBook to make sure you buy wisely!

1. A Sail Area/Displacement Ratio of 19.7 suggests that, in the right hands, the J/46 will have enough performance to leave most other sailboats of similar waterline length well astern. 

2. A Ballast/Displacement Ratio of 40.0 means that the J/46 will initially stand up reasonably well to her canvas in a moderate breeze, but she'll need a reef in the main to avoid heeling excessively in a gust.

3. A Displacement/Length Ratio of 161, tells us the J/46 is clearly a light displacement sailboat. If she's loaded with too much heavy cruising gear her performance will suffer to a degree.

5. The Capsize Screening Formula (CSF) of 1.9 tells us that a J/46 would be a safer choice of sailboat for an ocean passage than one with a CSF of more than 2.0.