@Tarnport
These sails are specifically designed to fit the peddle #kayaks made by #Hobie.
Unfortunately they discontinued the longer (16ft) version. Mine is vintage 2010 and is a great little sailboat when the wind is up.
The peddle system becomes the "center board" when #sailing so these boats can actually sail upwind!
This is great for just messing about, but on an actual trip the peddle system is so efficient you nix the sail and head directly upwind (rather than tacking with the sail). They excel with wind from the side or behind. They are very efficient tacking downwind with controlled jibes.
I'm happy to answer other questions...