It seems like a bad idea. Maybe if its a real short trip to get it from the beach to a ramp so it can be pulled out and fixed and the list is minor. Otherwise no way.
What are you figuring to do with the pontoon on the water? are you thinking about playing or are you worried about getting to the ramp to take it out for repairs?
I don't think anyone will tell you its a good idea to go out and play with a leaking pontoon, aluminum or fiberglass boat. but I think it would be a good idea to get that pontoon repaired so whats the plan here?