I put together this little blank with leftovers from another project.
2" thick X 43"X 19", roughly patterned after one of the Goddard templates.
http://mypaipoboards.org/interviews/LarryGoddard/Designs/thumb.shtml
Plan is two small keels near the rails.
I have my own opinions but I'd like to hear your input on rail shapes before I start to whackin' away at it.