this is what i pulled from the link for NC -- maybe Google it for your particular state as leo mentioned..
North Carolina: Recreational boaters can apply for a refund of the state sales tax on gasoline and diesel fuel that is purchased at a highway pump for use in their boats. The current refund is approximately $0.18 per gallon, after taking the current tax of $0.242 and subtracting a use fee of $0.06. The claims are filed annually, and must have original sales invoices attached. Boaters may claim a refund back three years, as long as they have the receipts attached.
To download form Gas 1201 directly off the Internet, go to
www.dor.state.nc.us/forms/ <
http://www.dor.state.nc.us/forms/>. Once there, click on Motor Fuels and then scroll down to Gas-1201. For more information, call (919) 733-3409.