I used it once when one of my engine hoses got a hole in it. Wrapped it up and actually left it on there for the weekend!!! I could not find another hose and it worked fine, just kept my eye on it.
Another board memeber hear got hit by a drunk boater and his boat sank in front of his house. My buddy took Duct tape and made a HUGE pannel out of it and then jumped in the water and applied it UNDERWATER!!!! It held on there well enough that we got the boat dry and Paul was able to drive it over to the nearest ramp and pull it out!!!!!
Lots of good uses for Duct tape, just DO NOT use it on anything in the sunlight or heat if you ever want it to come off