>Do you guys ever put a trickle charger on your boat's
>batteries if it sits outside? I use the Optima Batteries
>which are said to hold a charge for a year.

Moose, a trickle charger is a bad thing. It continuously puts out about 2 amps, regardless of the battery condition, and can damage a battery. Float charging is what you want, which maintains a current of less than 1 amp into the battery. Your Optimas should be fine if they are fully charged when parked.