http://www.ventureyachts.com/ph40shoalkeel.html
The Scheel Keel

http://www.designinc.com/Larina/keel.htm
Scheel Keel & Bottom Configuration IMAGES

http://www.cs.brown.edu/people/jfh/p...AQ/node16.html
What about keels?

http://www.pacificseacraft.com/cgi-b...tview.php?4416
Optional Scheel Keel

http://www.ikarus342000.com/Avorart.htm
ANTI VORTEX PANELS ? HOW DO THE WORK ?
"1. INTRODUCTION
Since about 1980 successful experiments have been made to reduce
leeway and improve the tacking ability of catamarans by anti vortex
wings instead of keels or boards. These are often called vortex
generators but this is misleading, because they should do precisely as
is explained later."

Very technical with drawings

http://www.kastenmarine.com/gaff_rig.htm
What's the Ideal Sailing Rig...?
Keel Profile

http://64.233.167.104/search?q=cache...el+Keel+&hl=en

Modifiying and existing Keel

http://closereach.com/csoa/cs30refit.html
STEP-BY-STEP REFIT
BY BOB KENNELL
Twelve Inches off the Keel, Please
When a frustrated lake sailor gets a chain saw in his hands, you'd
better watch your toes

http://www.geocities.com/bill_dietri...Hull.html#Keel

http://www.sailnet.com/collections/a...eid=caseyd0039

http://dan.pfeiffer.net/p26/keel.htm
Keel and Keel Bolt Servicing

None of that stuff works in real life. There's just no substitute for
a real keel.