The purpose of thigh braces...
Posted by: Celia on Mar-17-13 11:29 AM (EST)
is for proper boat control. Knees can be made to work but you'd better have ones that are a lot less bony than mine. It hurts, and it isn't good for the joints.
The above is if you want to have good control of the boat for bracing etc. For going straight on flat water without wind, it is less of a factor.
I think that the folder Chuck suggests may be an excellent choice. If you want to burn calories you can, it should escape registration requirements and will be able to handle your size.