Sure... Do you want to sell it or just value it?
Sell it, create a listing on the boat and a sign on the bow - Boat for sale. Pick a number. $1,000 - $4,000 - $10,000. If some one comes up and says I' give you $XXX. you just found out how much it is worth to that person.
Value it. Choose a number you would be willing to sell it for . You will be very close to a number a Value Number.
Note what you Value the boat at and what someone is willing to pay you money for the boat rarely are next to each other on the number line.