Towing is nice... But you are not supposed to tow most PWC without pinching off the cooling line. (According to the manual for my 4 stroke Yamaha VXR, and my older Sea Doo 2 stroke.) Yamaha even sells a custom hose clamp, it looks like a locking clothes-pin or a medical clamp.
Most models have a cooling line that is pressurized by the forward motion of the watercraft. If it is not pinched closed or disconnected, it will first fill the exhaust pipe and manifold with water. Then possibly the engine block through the open exhaust valve in the cylinder. Towing is restricted to slow speed and/or limited distance without precautions.
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Now for a cheap method - I tow mine with a piece of 1" pic pipe. Run a rope through it, with a snap hook on each end. First hook on the ski tow, or ransom tie down, other end on the bow of the wave runner. I use a 15' stick, it just fits in the floor locker of the Sun Deck, and keeps the PWC from ramming the boat when we stop. Runs just fine at 30 mph.