I am sure that sometimes you were fed up with you old, dirty covers. Perhaps it was made from PVC, or any other material, some mildew, some bird poop, salt from seawater, and some old unidentified whatever... everyone hate to touch and take off that cover. And at the top of all these sometimes it become very hot on the sun, am I right? Impossible to wash, and you don't waste time with high pressure cleaner.
Somehow our lake here at Balaton is very clear. No jokes, you can even drink at the middle of the lake. From my side I just give a quick bath sometimes to my Cover to let the dust and signs of leashes go. But it's not possible everywhere.
Here is an other point where we love so much the UV Covers. You think that it became dirty? Just put it in the wash machine, don't use detergent just some liquid washing soap, and start the machine at 40°C. Colder is also OK. Do not use dryer or tumble dryer (or on very low rev). You will be happy after that process with a looks like new UV Cover. Because UV Covers is washable. Unbelievable, right?