Assuming you hold insurance cover, you must inform your insurers asap, via your broker, of a potential claim. To delay in doing this could result a subsequent claim being time-barred. They should then appoint a Surveyor to check out the boat and the engines and determine the cause and extent of damage, also cost and nature of repairs. A joint survey will probably be carried out jointly with a Surveyor appointed by the dealer's insurers, assuming the dealer is insured of course. On receipt of the survey reports, the two insurance companies will then get together and thrash out the processing of the claim.
Meantime, I suggest that you keep a tight hold on your 7k, despite the 'nice guy' dealer and his promises. When you have someone by the balls, their hearts & minds will surely follow! Good luck.
If You're Thinking About It, Do It!