I don’t know if you have been following any of the "hacking" or "Make" movements that have been picking up on the Internet of late, but the move of people more toward repairing and away from tossing and buying has been growing.
Boaters tend to be self-sufficient types, and usually have something that needs repaired.
This stuff is a silicone based "plastic" that you can mold at room temperature and then it hardens. The developer states that:
Yes sugru has very good UV resistance and we use UV resistant pigments as well; sugru has been used outdoors and even in and out of the sea for more than 2 years without any degradation signs except wear and tear.