In the southeast, most of the inshore fishermen use the Polar Bear Cooler. This softside cooler is the number #1 rated cooler in the southeast. If you are out fishing and spot someone with a Polar Bear, just ask them how they like it.... be prepared to be there for a while to listen to them telling you how great they are
The 24 pack fits perfectly
behind the seat of the Revo/Outback/PA. While they also make a 12 pack and 48 pack, the 24 seems to be the preference of the kayak fishermen. It will easily hold drinks/snacks/couple of reds. Most folks down here use fish condums (plastic bags) to put their fish in before putting in the cooler.
They aren't cheap but you get what you pay for