My kayak footpads are shortened all the way and a self rescue instructor noticed this and suggested I get some foam to extend it an inch to 1 1/2 inch and duct tape it for better control. Not being a fixer upper, I'm not familiar with materials (I know what duct tape is). What kind of foam should I use so I'm not constantly have to replace it and where can I get it. And is there such a thing as marine duct tape? If there is, where would I get that?