Mike is right. You can take an old boat and cut the tip off, soften it with a hot air gun, and mold it to the new boat. Glue the tip on over the old part and puff getto awesome. But, knowing how thick the plastic is and how much you would need to stretch it... your better option would be to find the next boat up in size. - to fix an EZ you would weld/ glue on the tip of a Big EZ.
There was a company that made caps for random tip shapes called Ram Caps. I had one on an old crosslink boat that got drug behind a canoe trailer coming home from the Top Yough once. It never came off and lasted longer than any other part of the boat. Ram Caps came in five shapes and were more of a hard rubber than thin plastic. Check with Wildwasser they used to sell them a long time ago. Or, do a search for Ram Caps.
Pyranha made ones for a couple of their creekboat designs. They worked well if your shape was spot on with theres, if not they didn't realy mold to fit as well as you would think. The Pyranha caps were more plastic than rubber. A thin linear plastic.
I love to dance, but who needs the music- It throws me off.