A couple of questions:
Did you make your offer "subject to survey & sea trial," or is the survey only a C&V ("condition and value") survey after the fact to satisfy the lender/insurer? If it's the former, I'd be very leery of any surveyor recommended by the broker...because sellers aren't obligated to reveal ANYthing they may know about a boat, and the whole purpose of a full pre-purchase survey is find any problems that could cost you--the buyer--money later. If it's the latter, as long as the lender and insurance company are happy with that surveyor, that's fine...although you have to pay him, he's really working for them, and all they care about is whether the boat is worth what you want to insure it for and whether it's likely to stay afloat...if the toilet quits or the fresh water pump fails or you find a soft spot in the deck or the boat has blisters, that's your problem, not theirs. A survey rarely includes any more than a cursory inspection of the engine--just to make sure it's actually there, runs, and is or isn't spewing fuel or leaking oil. The surveyor will also inspect the fuel system--hoses, hose clamps etc--to make sure it meets all the standards, but that's about all. You'll have to hire a mechanic to do any deeper evaluation of the engine and/or genset .