If you are going to be financing a portion of the price your lender will most likely require the Hull Identification Number (HIN) and the serial number(s) for all engines on the boat. Some lenders and insurance agencies will have their loan contingent on a survey with a market valuation. Others will take a NADA valuation figure. When you are contacting different lenders about rates be sure to ask what is required if you don't intend to get a survey. It is good to get pre-approved prior to making your offer to ensure there are no hiccups for payment on your side. There are companies like Essex credit that specialize in boat loans if your bank doesn't do that sort of lending.
When you make your offer it should be contingent on a survey and sea trial. This is for you to get a good feel for the boat and you can decline the purchase or negotiate a better price after these inspections. A competent surveyor will also bring to light any defects so you can know what exactly you're getting into with your new purchase.
When your offer is accepted you should schedule a survey and sea trial with a certified marine surveyor. This is where you will likely find out all the faults with your new boat. You can hire any surveyor you wish but you will almost always get what you pay for. A survey can be expensive but it's better to find out your keel is going to fall off during the survey instead of on your maiden voyage. The Society of Accredited Marine Surveyors offers information on their accreditation and links to local surveyors. Get recommendations from local sailors or the site. The surveyor will be working directly for you, not your broker or anyone else. Be sure to research and interview him just as you would anyone else that would do work for you.