Twin Keels - SailNet Community
LinkBack Thread Tools
post #1 of 2 Old 01-31-2002 Thread Starter
Join Date: Dec 2001
Posts: 47
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Twin Keels

I recently bought my first real ''cruising'' boat, a 1974 32'' Westerly twin-keel ketch. She seems to be a strong, well-built boat, and was the final result of a 2 year search; the shallow draft of the twin keel being, IMO, an advantage for Caribbean cruising and the like.

Ive heard stories about the odd steering characteristics of twin keels, especially to windward, and the partial-skeg rudder seems very vulnerable.

Any comments on twin keels in general or Westerlys in specific would be appreciated (looks hopefully to Jeff_H, who seems to have an encyclopedic knowledge of old boats)

Ive often wondered why twin keels never got popular in the US... is there a reason Im not aware of?

EtherCat is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
post #2 of 2 Old 02-01-2002
Jeff_H's Avatar
Join Date: Feb 2000
Location: Annapolis, Md
Posts: 7,039
Thanks: 5
Thanked 176 Times in 143 Posts
Rep Power: 10
Twin Keels

Westerly''s bilge keel boats were very popular in Europe but found a comparitively small market over here. While ''mud berths''(the boat sits in the mud at low tide) are quite popular in England, They really have not caught on over here.

There are a lot of problems with bilge keels on small boats. Although each keel is smaller than they would be as a fin keel their combined surface area and frontal areas results in enormous drag. This results in a boat that is slower and less reliable in ''stays''. I used to teach sailing at a small charter fleet down in South Florida that used a small fleet of Westerly''s. They had a mixture of both fin and bilge keel versions of the same model. It was very apparent that the bilge keel model was much slower, more tender and did not go to weather as well.

The other issue with bilge keelers is that when you run aground you are really planted. You are there until the tide rises.

Design and engineering of bilge keel boats is tricky as well. The individual fins need to be designed to provide lift when the heeled over as well as vertical, with only one keel providing primary lift and yet minimize drag produced by the other fin that is not providing lift. Additionally the two keels tend to be low aspect ratio foils and so produce less lift for their drag.

More controversial are issues related to interaction between the two foils. As a boat moves through the water there is a zone of turbulent and disturbed water that extends outward of the foils. I have seen it posed that on small boats with bilge boards there is an interference between the fins that further reduces lift and adds to drag.

All of that said, the small Westerly''s have done all kinds of voyaging and offer a lot of boat for a limited budget. Skip Beaufort''s ''Water Dog'' (might be ''Water Puppy'' but I think that is the dinghy''s name.)spent many years cruising the Bahamas and Carribean.

Jeff_H is offline  
Quote Quick Reply Share with Facebook

Quick Reply

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Forum Replies Last Post
Fixed or swing keel, which is better? TimG2 General Discussion (sailing related) 17 07-30-2014 10:23 AM
Fin Keel or Shoal Keel acmecoyote General Discussion (sailing related) 11 05-06-2011 05:39 PM
Wing, fin, or bulb...what are the trade offs? langousta Gear & Maintenance 17 09-17-2008 05:54 PM
Twin bilge keels? sdwyer Boat Review and Purchase Forum 9 11-27-2002 07:54 PM
twin keels as an option tomcostin General Discussion (sailing related) 4 06-17-2002 10:55 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome