This has been discussed here a time or two. I just found this link that might help some of you out. It can save you A LOT of money.
For those that don't the specifics you only pay sales tax on the actual vessel in FL, NOT the whole purchase price IF you document the transaction properly. Many people way over pay.
Details below. Doesn't work with "Dealers" or I/O's. I always have line on the detailed bill of sale for electronics, equipment, motor, trailer and anything else significant in the transaction.
TL-08 section II, C, 14 (page 6)
http://www.tc.citrus.fl.us/tl-08.pdf
14. An exception to the payment of non-exempted sales tax on a complete vessel rig may be made if the applicant furnishes a properly executed itemized bill of sale which separately describes and itemizes (prices) all items including the vessel, outboard motor and trailer. In such instances, only the vessel and
trailer will be subject to the payment of sales tax.
It helps to take this in with you sometimes!