I've broken all of the rules for different reasons. My first boat had 20 hours on it, still a new boat so I bought it without a test. It was as expected. My waverunner was owned by a commercial pilot with big plans but no time, he bought it drove it three weekends, put 15 hours on it and again, was still a new boat, bought it without a test...again it was a new boat having gotten three weekends of use total and he threw the nearly new boat lift in. My current boat was a hard to find model and was advertised by the owner for a couple weeks before he pulled it out of winter storage. As you can imagine, there were seven people in line to buy it all awaiting the day he pulled it out of storage. I got the first appointment and other buyers started showing up at his house. Boat had just over 200 hours on it but still nice and well maintained and I had been searching for quite a while for the exact boat with the hard to find 350 mpi so I bought it without a test. True to his word, the boat was exactly as described. Two of the boats were nearly new and a test was 'arguably' not a requirement but the third boat, the moment, the scarcity, the time of year, and the fact I was boatless having sold my previous and so no boat on my boatlift at my lake house got the best of me. A test drive meant, the next guy standing in the culdesac got the boat and I was willing to bet the guy was honest and willing to take the chance for the exact boat I was seeking having been in the market for so long.
Also, the minimum price for an actual survey is $2,000 in my neck of the woods. Fine for a larger boat maybe not so much for other boats.