Thanks for the advice. I guess I needed to see for myself . Actually, my NDK covers have a teeny- weeny tab but I don't see how I can attach a reasonable cord to that. I have a Valley cover coming, decided to get an emergency neoprene one as well. I took a sturdy garbage bag and cut it in 3 pieces to cover the hatch. Affixed them with 6" bungee loops (the ones with the "ball" attached for easier removal), one over the other and put duct tape over the whole thing. 4 hours of non- stop rescue drills, in-out-in-out, not one drop of water in day hatch. I'll always take garbage bag, bungee loops and duct tape on bigger outings. But you're absolutely right, it shouldn't have happened and in conditions I would have been in trouble!