It can take a while to work out how to fish on Radiation Island so this is a guide for it.
How to fish: First find a fishing rod or craft one (wood and string).
Then go to a body of water and keep on going until a fish symbol appears instead of the hand with a sword.
Then tap it ONCE. When the string seems to go to the side tap the fish again. Then if a fish appears in your inventory you have being doing it right.
Is an easy way to get lots of fish. Is found when digging in groups of 1-4, or in a chest. To dig craft a shovel with smelted iron, wood and string.
Raw fish gives back half a food bar but can go further if cooked in a furnace. When cooked it gives 3 cooked meat that gives back three quarters of the bar.