The Shearwater 45 Sailboat
Specs & Key Performance Indicators

The Shearwater 45, an aft-cockpit cutter, was designed by Dudley Dix and built in South Africa by Acheson Yachts.

'Maggy May', a Shearwater 45 long-distance cruising boat on a mooring ball in Jolly Harbour, AntiguaA Shearwater 45

Published Specification for the Shearwater 45

Underwater Profile: Fin keel & spade rudder

Hull Material: GRP (Fibreglass)

Length Overall: 51'5" (15.7m)

Waterline Length: 37'5" (11.4m)

Beam: 13'1" (4.0m)

Draft: 6'3" (1.9m)

Rig Type: Cutter

Displacement: 27,550lb (12,497kg)

Designer: Dudley Dix

Builder: Acheson Yachts (South Africa)

Year First Built: 1990

Published Design Ratios for the Shearwater 45

1. Sail Area/Displacement Ratio: 20.2

  • 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: 38.0

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

3. Displacement/Length Ratio: 235

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

4. Comfort Ratio: 33.3

  • 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 Shearwater 45

1. A Sail Area/Displacement Ratio of 20.2 suggests that, in the right hands, the Shearwater 45 will have enough performance to leave most other sailboats of similar waterline length well astern. 

2. A Ballast/Displacement Ratio of 38.2 means that a sailboat like the Shearwater 45 (which doesn't have its ballast concentrated in a bulb at the foot of a deep keel), is likely to benefit from being reefed early to keep her sailing upright in a moderate breeze.

3. A Displacement/Length Ratio of 235, tells us the Shearwater 45 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 33.3 suggests that crew comfort of a Shearwater 45 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 Shearwater 45 would be a safer choice of sailboat for an ocean passage than one with a CSF of more than 2.0. 


Other sailboats in the Shearwater range include:

Recent Articles

  1. Used Sailing Equipment For Sale

    Jan 21, 23 01:37 PM

    Here's where people with sailing equipment for sale advertise their stuff entirely free of charge. If you're looking for used sailing gear or other used boating accessories, here's where to find it!

    Read More

  2. 'Sea Wraith', a Hustler 35 Sailboat for Sale

    Jan 21, 23 08:28 AM

    The Hustler 35 sailboat is a hugely capable classic offshore cruiser. My 'Sea Wraith' has recently had an extensive mechanical and equipment refurbishment to ensure she is absolutely ready to take on…

    Read More

  3. Popular Cruising Yachts from 50-55ft (15.2m to 16.8m) Length Overall

    Jan 11, 23 09:07 AM

    Large, well-equipped cruising yachts of this size can cross oceans in relative comfort and speed, but you'll need deep pockets to operate and maintain them.

    Read More