Which brings up an interesting point..... Just about everywhere you run into "No sea trial without an accepted offer/executed contract".....
Chicken < - > egg..... Guess it depends how bad they want to sell it if they'll take you for a ride prior to making an offer?
Or do you make a deal subject to quick sea trial with right of refusal and then a survey? Would you then be waiting for a deposit back? Why go through all the trouble?