The Sunfish I bought for my daughter is so old it does not have a storage compartment in the back of the cockpit. I have thought about adding an inspection port to the back of the cockpit so I can ventilate the hull and to allow installation of a hiking strap. I saw this really cool water bottle holder that fits into the Ronstan 5” inspection port. Has anyone tried this on a Sunfish and would it work without interfering with the hull foam? I don’t know if there is foam on the centerline in the back of the hull that would interfere with.
I have seen a photograph of the foam in a newer design boat but I have no idea where the foam is in an old style pre-1972 boat with the bronze rudder system and the lack of a storage compartment.
I'm pretty sure that the foam blocks in the pre-1972 boats are in the same location. You shouldn't have any problem installing the port in the back of the cockpit. I installed a dry bag in the front of my cockpit and it really works well.