You have to make an offer and come to an agreed price, like a serious buyer would. Then you put down your (usually) refundable deposit and go for a sea trial.A sea trial is the marine equivalent of a test drive, crucial for assessing a vessel's performance before it is fully commissioned or sold. A sea trial is totally out of the question. Is it OK to just get a marine survey done with the boat out of the water? A sea trial or trial trip is the testing phase of a watercraft (including boats, ships, and submarines). It is also referred to as a shakedown cruise. After successfully completing trials of the flipping operation, it was towed to San Diego to commence operations in September 1962. Sea trials are an important step within the boat buying process that allows you to take a boat for "test run. Appendix A of this chapter contains a glossary of terms used in this specific volume. c.