Catch and release, ice and a oxygen bottle. You'll never lose a fish. You can order the correct diffuser, hose, and regulator on eBay. Buy the small oxygen tank from a welding supply shop. They just swap it out when it's empty like a propane tank. About $250 for everything depending on tank size. Small price to pay to not lose a fish. 1 dead fish could cost you way more. Plus, the pure oxygen comes out cold which cools the water by itself
I've never heard of this. Isn't pure O2 highly combustible and highly pressurized? How do you stabilize the tank in the boat to make sure it's not get knocked all over the place during runs? Not saying it can't or shouldn't be done, I just haven't heard of it and would have some concerns.