If you are doing clips that you are going to splice together later and you don't want to surf through a whole day of fishing, you can try what I do.
If I catch a fish worth putting out there for people to see, I'll land it, unhook it, show it to the camera, etc. At that point, I will stop the video and re-start the video. That way, when you get home you will be loading a couple (bunch) of smaller clips and at the end of each "important" one will be the fish you want to put in the vid.
Sounds very rudimentary, but it's effective.