I would totally marry West System...
G/Flex is awesome for a permanent in-shop repair, but not really workable in the field. There is this stuff for surfboards called Board Bog which is super easy to apply in the field and stays on until you want it off. Supposedly, it also sticks to plastic -at least plastic SUPs. Imma get some for my composite boat and try it on the plastics. http://www.boardbog.com