Dude I feel for ya! I fish as a co-angler in my local bass club, so I have some experience fighting for bites and trying to find a limit all day. My best advice is to be super observant of your boater and how he is catching his fish. If for example he is throwing a 3/4 once football jig offshore, than you could pick up a big worm or swim bait. Don't throw the same bait as him, just fish the same water zone. I also try to scale down my presentation to catch more bass, or the more finicky fish he might of missed. Like I said, be observant and try to find something or catch on to a pattern he hasn't figured out yet, and you'll always be successful out of the back of the boat.