Most ski rope is the
braided polypropylene rope that floats. It jams even with the best of knots—the bowline. The loosening process in any kind of rope can be started by hitting it with a hammer. (But not while attached
to the boat

).
Braided polypropylene has the saving grace that it is easily spliced.
To make a new loop, just cut off the frayed part, tape the tip, and thread the loose end back through any part of the standing line. (For about nine inches). Easy-peasy.