Everyone is different. We do not see the boats we rent as hotel rooms for a spring break or bachelor party where we pay for a few nights in a large corporate property and disappear.
"It's a rental" comes to mind. A $5,000 cash well in advance deposit can help clear up that misconception.
We do see the boats for what most are. A large piece of private property that we are allowed to borrow for a week or more for a fee. We try to treat them like our own boats. On our own boats we are responsible for X amount of damage or loss each day we own them. We consider whatever the amount of the deposit a part of cost of the adventure. We wire those funds in advance with a clear record from our bank. If something happens on our watch the funds are already paid. We also carry our own global insurance coverage that extends to hired and borrowed vehicles/vessels. At the end of the trip if the deposit is returned we are ahead. If something happens the funds are already paid and the amount was in the original budget. After tens of charters we have only consumed some of our deposit twice. Once in Florida the boat inspection the day after we left revealed a scratch we do not recall doing. We just let the few hundred dollars go. In Maine early one morning we ran a large power boat onto some granite. We did it. There was no one else to blame. Weeks later after the boat was dried and repaired we received the remainder of our deposit back along with a complete itemized yard bill.
If there is anyone getting rich in the recreational charter boat industry please point me in that direction. I want to buy in today. The industry is capital intensive and hard work for everyone. The list of bankruptcies and broken marriages is long.
The marketing companies have long been desperate to make vacation boat charter as simple as the corporate hotel business. As the capital investment/insured value of these ever more complex vessels grows that will be harder to do. Taking clear responsibility for the first $5,000 of a assets insured for greater than $500,000 is a good practice all around. Enjoy the appearance of a "free" ride while you can.