BTW...unless the boat is new...it is gonna have some problems. Your goal is to :
1. Identify as many as you can before you spend your money.
2. Reduce the price of the boat from it's market value to cover the costs of repairs on any significant items.
Once you've made your offer and gotten it accepted based on the KNOWN faults of the boat...then your surveyor will discover the unknown faults of the boat and the negotiations can begin again or you can walk away if the faults are too great.