The cut out in the transom is so I can kick with my legs for propulsion if needed (I have a couple of flippers I took on the boat with me) This also makes tacking a very quick process.
I am using an Optimist rig, stayed with some dyneema rope. The hull itelf is made from a foam core sandwiched between two sheets of 3mm plywood so the hull is very light!
I made a hand stearing mechanism for the rudder using two cables lead through some pulleys to a lever where my right hand falls naturally. The main sheet leads to a cam cleat in easy reach of my left hand.
I was pleased at how comfortable it felt laying on my front - this was one of my worries. The steering mechanism did not work well but I managed to steer by just using my foot on the rudder. The boat seemed balanced well, with maybe just a little too much weather helm.
I need to add a little more buoyancy on the sides and aft, I shall do this with some closed cell styrofoam. I am also going to change the steering mechanism, I am thinking at the moment to change to a foot controlled mechanism.