Since the dinosaur has been bumped on this thread, I'll add on....^^^this is great advice, but if you do not feel comfortable doing so PLEASE DON'T. I'd much rather take a few extra minutes to do it myself than have someone unfamiliar back my trailer/boat into a dock or another rig on the ramp. Goes with helping out with anything, if you're not 100% confident in doing it, it's ok to admit it and let the boater work around you. I had a guy fish with me once who was going to hold the boat by the dock while I parked the vehicle/trailer. I come back to find him holding onto my trolling motor shaft that he for some reason had removed from the bracket in one hand and clinging to the dock for dear life with the other. Luckily he didn't drop the TM or fall out of the boat since the current was trying to pull the boat away. Same goes for netting fish (if allowed) Have an honest conversation before the day begins about it and be honest about where you're at with it.
Also adding that as a co, you need to keep your gear neat, organized, and stowed the majority of the time. If you pull a tray out to tie on a new bait, put it back when your done. That way when it's time to move, you're not leaving the boater waiting on you. Time management is critical in a tournament and it goes a long way with a boater that when he says it's time to move, your ready to move.
I want to add everyone may have a different demeanor on the water and many times how the day is going will dictate the conversation. If it's a tough bite, or the boater is struggling to catch fish there may be very few words said. If this is the case, don't immediately jump to the conclusion that your boater is a jerk and doesn't want you there, but rather is most likely concentrating on what he/she is doing and trying to figure the fish out in their head.