Here's some opening horse traden questions [and statements]; i.e. getting to learn a bit about the boat and the seller's attitude [need/desire] to sell the boat:
1.
How long you owned this boat? - If short time [months to minus two years]... seller probably not too attached to the boat; may be ready to dicker-quicker. If a longer time [two years to..??.. years]. May be in love with boat; could make getting reduced price a bit harder.
2.
Why are you selling this boat? - Should let you know at least a bit about how much leverage you have for helping the seller to attain the reason/desire for selling.
3.
What are your three favorite items about this boat? / What are the three things you would change about this boat? - Lets you know if the boat actually satisfies the seller or not. Use that knowledge in your price offer reasoning.
4.
You have a complete log/receipts accounting for all work done to this boat? Seller's answer to that means a lot... too much for me to get into during this short post.
5.
I have cash available. After you and I have thoroughly gone over this boat's qualities and downfalls I will make you happy if the boat meets my criteria and my needs. I like the boat. - Puts the seller at ease that you are a real buyer and that you just may be the buyer to fulfill the seller's desire/need to sell the boat.
6.
You have a recent [within last two years] survey on the boat? - If so, read it well. Even if so and especially if not - Tell the seller you are going to have full hull and mechanical surveys done. Watch seller's reaction carefully. Again, similar to #4, too much to get into during this short post.
7.
Soon as you and I get preliminary sales papers set up and my 100% refundable down payment in your hands: I can hardly wait till we get chance for hull survey and for a really great sea trial with mechanical surveyor aboard. When do you think we can do that... tomorrow, this week or very soon? - If seller jumps at the chance to set up papers and to show the boat in action means the boat is probably in OK condition. If the seller hesitates... things may not be so good.
All in all - The sale and purchase of a boat [actually of anything] is a dance that should be carefully orchestrated from, in and on each side. In my opinion - TRUTH Rules! Whether being the buyer or the seller... as long as truth is told regarding all portions of the negotiations then the outcome [if purchase ensues or not] can be solidly felt as being okay. A learning experience if you will.
Happy "Boat Buying" Daze! - Art