What he said: "Contingent on survey and sea trial"
BUT - if you buy now you'll be taking the boat over now and in five months it will be passing hard to back out of a deal. Especially if the owner has used the money to pay-off any mortgage on the boat and it's been registered in your name for "X" many months.
You can insist on a large escrow set up to help correct any problems, (i.e. $5,000 for the motor, $2,000 standing
rigging, etc.) but I would only purchase a design I was familiar with and knew satisfied my desires at this point for a boat on the hard.
The good news is that a boat out of the water a month can be a good one to check with a moisture meter for hull problems.