Bring a towel with you it is great to lay the fish down on so they dont get all dirty from gravel and such. Wet the towel first lay it on the ground then just lay the fish on that.
Prep your photo area as well have it all set up, if your taking self portraits take a few test shots before you get the fish in the boat, it will make things much quicker and easier. Lay the measuring tape out before hand.
Another cam tip is, always make sure you have extra batteries, especially during the colder weather the battery's cant take pics if they die!!! I use rechargables much cheaper and reliable!!! Hope these tips help to get you started.

Mike :)

Better to be loose then tight!