Pics would help, but that boat has a doghouse that covers the engine, doesn't it? Usually the battery would be under/behind the seats next to the doghouse. There might be an access panel at the back of the enclosure under the seats.
You could also trace the red wire coming off the starter back to the battery...
Yeah i found were it once was now gotta buy a battery it was in a cubby next to the motor dog house i do have another question tho every other regal medallion ive looked up has a mercury in board motor where my appears to have a chevy v8 so im a lil confused by this
