first hand of a guy whose family business did this or years. They owned a boat, jet skiis, 4-wheelers, etc. They used the 4-wheelers on job sites as 'transportation' (when they weren't using them in the mountains camping), the boat and jet skiis were used about 30 times a year for business entertainment. The other 10-20 times per year when family wanted to use the boat, they paid $100 a day to rent it.

All of it on the books, all of it allowed during an IRS audit in 2003. The auditor had absolutely zero issue with it, because they documented everything. He said he could probably have dinged them on what 'fair market value' was for the daily boat and jet skiis, but his comment was "do you know how many of those things are just rotting in a side lot and not getting used at all? at least you cover your annual depreciation with personal use rentals".

So it can and is done.