I'd wait to see what the surveyor says on the boat and as I mentioned above, make sure they have moisture meter reader/rubber mallet to go over the boat with. If they don't, spend the $50 or so and get one yourself to bring with you when you inspect the boat with the surveyor. Also as I mentioned above, it looks like it could be an issue with some water intrusion but also some rusted hardware. As you mentioned, it's a 14 year old boat and the bolt threads going into the stern could have some rust on it, which would account for the water stains. To me, it doesn't sound like the seller is hiding anything as it seems unlikely that a seller would agree to a surveyor to inspect the boat if they were trying to hide things. The other picture you posted looks to show a very clean/tidy looking boat, which if you crawled all over it and only found the one potential issue, I'm thinking you've found a decent boat/seller. Pending a favorable survey, I'd then back the swim ladder hardware out, get new hardware and reseal it. I also was out $600-$700 when I paid a surveyor to go look at a boat for me that was out of state and that boat came back as not being in the condition it was advertised to be in. It was frustrating to be out the $600-$700 for the surveyor, but if it keeps you out of buying a can of worms, then imo it's money well spent. If you do drive the boat on the water back to your home port, I'd obviously run quite a bit of fuel through it and make sure everything is running/working fine before taking off. On top of that, I'd check to see if you have a Sea Tow membership on your insurance in the event that you break down or have issues, especially depending on how far of a ride it is from one location to the other. In regards to your contract, or potential contract, I'd say the deal is contingent upon a favorable survey/sea trial run, and make sure you note that the down payment or whatnot is refundable in the event that there is an issue. On the flip side of the coin, there is always a possibility that the seller had the boat surveyed in 2019 and there wasn't an issue at the time but there became one over the last 5 years. Doing your due diligence, hiring a good surveyor and listening to what they have to say I think is going to be your best bet.