Thanks so much for all of your input; this is such a wonderful forum with very knowledgeable participants.
This is a private mooring with polypropylene pendant, a soft inflatable ball with 12’ of 5/8 ” chain off a shackle to the bottom turnbuckle with 50’ of 1” chain to a 200lb mushroom. I'm thinking of encasing the 5/8” chain in a flexible tube to provide scratch protection, but the ball still gets dirty and can become abrasive. I like the idea of a drogue on a short line, but it will collect lots of weeds making it a pain to deal with. I already have a landing line for my jet ski that is attached to the stern with a float that would provide some visibility to anyone coming too close. We use the Jet Ski for transport to and from our dock. I see how a rigid PVC pipe could keep the boat from getting on top of the mooring, but I don't see how it would be effective in keeping the boat off the mooring ball. It may help to keep the boat away from the mushroom, a real problem in the ELK with big tides and shallow waters. I have tried to mitigate this risk of damage by wrapping the mushroom bell edge with a motorcycle tire cut in half and bolted back together again, that way if the shoal keel gets on top it will just hit rubber. I’m still worried about the ruder hitting it. Thanks for your input.