Originally Posted by bad_moose
The tape snapped 4 times, causing the boat to roll off back into the water, blocking the entire slip and causing a nasty hazard for everyone nearby. It's amazing he didn't get whipped in the face.
Which is why they usually have polyester or polypropylene webbing rather than nylon. Low stretch means low kinetic energy to be released.
Told this before, but I'll refresh your memory:
A buddy of mine was launching his boat, but it wouldn't come off the trailer. Pulled up the ramp a bit, backed in and hit the brakes. Still wouldn't launch. Repeated the maneuver with a bit more gusto, and the entire contents of the back of the pickup gracefully slid out of the bed and into the water. While picking up the assorted dive cylinders, spare parts kits, coolers, heads of lettuce, bags of bread and whatever else that was floating around the harbor, he found he had neglected to remove one of the two transom straps. Undoing it caused the boat to spring free (nearly knocking him out), and let the trailer drop (nearly crushing his foot.)
Story Moral: Put your tailgate up. Or, undo ALL the straps. Take your pick.