If you want a test drive, that is fine and I would be more than happy to take an interested buyer out for a test run, only after we negotiated a price and they place a deposit. There are too may people out there wanting a boat ride with no commitment.
Also, I have found this very annoying (for me) practice creeping into the used market lately, where people ask you what is you best price. I now place a comment within my advert as follows:-
"Please do not ring or message me asking my best price.... The listed price is clearly visible. If you are interested, please send me an offer or better still come and have a look and then I will be happy to negotiate $$$$...."