Here at Lake Powell which has all sorts of unmarked hazards they rent out all sorts of very expensive boats and water toys to people with no experience or knowledge of the lake or boating. As an example you can rent a 75 foot houseboat and they will pilot it out of the slip to the marina breakwater, hand over the wheel, jump on a skiff and head back to the marina. They encourage you to buy the insurance as it is easier to make their money but as they have your credit card and verified information they really don’t care. Because the company does their own repairs in a remote location they charge excessive prices, verify their own repairs and do the work to their standards as they basically have a legal monopoly they make a lot of money. You have a choice pay a smaller excessive amount for their insurance which covers everything and not worry about tearing up anything while learning or basically potentially pay more than the unit is worth for a few days use. Get the insurance, go have fun learning where you want to go but be sure to ask about trip interruption insurance as well and maybe it won’t cost you anything in the end!