Marine Fuel Tax Refund
Recreational boaters who purchase fuel for use in their boats may be eligible for a full or partial refund of the taxes paid on the fuel: These taxes are usually used to repair highway damage caused by the wear and tear of automobiles. 

Because boats do not cause this damage, many states apply the tax on marine fuel to boating programs through the Aquatic Resources Trust Fund. In states where the money is not applied to these programs it is usually put into the highway improvement fund. 

A number of states, recognizing that it’s unfair to use boaters’ tax dollars for highway improvement, offer refunds on marine fuel taxes. Procedures and qualifications vary by state, but typically, a boater will need to save his/her fuel receipts as well as complete some type of paperwork (often available online).

The following links list states that offer fuel tax refunds
http://www.americanboating.org/fueltax.asp
http://www.boatus.com/gov/state_taxrefund.asp

Though not included on the above sites’ lists California also offers boater’s tax refund. Get details at these sites:
http://www.boe.ca.gov/pdf/boe770du.pdf
http://www.sco.ca.gov/col/taxinfo/gtr/index.shtml