Instead of refinancing, try this
Most lenders would rather do what it takes to keep your business than let it slip away to another lender who's offering lower rates. Find out what the current prevailing rate is, and then ask your current lender to match it if he wants to keep your business. Odds are 99% that he will unless you've been late with payments or your credit report is shaky (in which case, you prob'ly couldn't refinance--at least not at any better rate--anywhere else either).The loan isn't re-written...the only change will be the rate at which the balance of your loan is charged, resulting in either lower payments from now on...or, if you're smart, you'll continue making the same payment amount, applying the difference to the principle, paying off your boat several years faster.