Sort of. A low speed wing needs some thickness but actualy still needs to be concave on the "underside". This varies with the lift/drag required as well. (windward or leeward again)Some thickness is always required, and better than none.
If Hobie Bob was symetrical and stretched for the length of the square head, this would be an improvment, because it would also help out the end plate effect (See other thread). However I dont think it would be that hard to make an articulated one. Say a alligator (kids toy) looking bunch of foam segments that radiused into each other with a batten looking thing spine. The fit need not be perfect (actually a gap is prefered) just so long as the flow can stay attached.
Reading back over: If you follow that, you get a prize..