The Nautor Swan 51 Sailboat
Specs & Key Performance Indicators

Published Specification for the Nautor Swan 51

Underwater Configuration: Fin keel & spade rudder

Hull Material: GRP (Fibreglass)

Length Overall: 51'3" (15.6m)

Waterline Length: 42'4" (12.9m)

Beam: 14'8" (4.5m)

Draft: 8'11" (2.7m)

Rig Type: Masthead sloop

Displacement: 39,600lb (17,962kg)

Designer: German Frers

Builder: Nautor Swan (Finland)

Year First Built: 1980

Year Last Built: 1985

Number Built: 36

Published Design Ratios for the Nautor Swan 51

1. Sail Area/Displacement Ratio: 17.9

• 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: 41.7

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

3. Displacement/Length Ratio: 233

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

4. Comfort Ratio: 38.0

• 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: 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 Nautor Swan 51

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1. A Sail Area/Displacement Ratio of 17.9 suggests that the Nautor Swan 51 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 41.7 means that the Nautor Swan 51 will stand up well to her canvas in a blow, helping her to power through the waves.

3. A Displacement/Length Ratio of 233, tells us the Nautor Swan 51 is a moderate displacement cruiser, which means she'll carry all your cruising gear without it having a dramatic effect on her performance. Most of today's sailboats intended for offshore cruising fall into this displacement category.

4. Ted Brewer's Comfort Ratio of 38.0 suggests that crew comfort of a Nautor Swan 51 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 tells us that a Nautor Swan 51 would be a safer choice of sailboat for an ocean passage than one with a CSF of more than 2.0.