Not really, although like any other towing (cars/trailers, trucks/boats, boats/tubes) it does make the engine and driveline work a bit harder. As long as your engine is running correctly and you are maintaining pump oil, shaft grease, plugs, etc....Tow away.
I think what is a amusing is the most common damage to the craft while towing is from the rope. Once it a while someone runs over the rope when turning around and sucks up the rope into the impeller.
Because a PWC hull is not quite as efficient as a full size boat hull, you need to make sure the rope on the tube is set to above the water line to prevent the tuber from nosediving (too easily).
