Just like a car, selling your boat to an individual is always better than trading it in. An individual is going to keep your boat. A boat dealer is going to re-sell your boat. Back when I had 2 boats, I spoke to a local boat dealer about trading them in on a new boat. They wanted to give me $10,000 for both. I got $16K selling them to individuals.
2001 Triton Tx-21/225 Mercury EFI