I would expect the sales tax on this exchange to be a mess. You need to figure out in advance whether you can escape with 5% on just half the value of the boat. Whereas the departing partner was the name on the registration, I would expect the state to want %5 on the full value of the boat to put either one or two new name s on the registration. The existing partner is not likely to want to pay half of the 5%, he may want you to pay the whole amount. i would get this issue figured out before you sign any papers.
Certified...in several regards...