My question involves a consumer law issue in the State of: Washington & Oregon

I bought a boat with an ex boyfriend. The loan was in my name. He has the boat in his posession. I paid off the balance on the loan of $17,000. He was initially making the monthly payments to me while I made the monthly payments to the loan. Then we broke up. He stopped paying me but I had to continue the payments to the bank. I finally paid it off due to so much interest accumulating. he said the boat was a lemon and he never even went out on it. I just saw his Face Book page and he has pictures of it in the water bragging about it taking it to the San Juans. It is technically my boat but I never got any kind of title to it from the bank. What can I do? I just want him to pay me or sell the boat and pay me back.