Wash and dry filets. Pat dry with paper towels. Cut into smaller increments (about four per filet); set aside.
In another flat bowl, beat the eggs and water together.
Place the flour in another flat bowl.
In another flat bowl or pie pan, crush the coconut and Panko together to break up the coconut chips.
Dip each filet into the egg mixture, then into the flour, and shake off excess. Then press each filet into the coconut breading mixture until coated.
In a large frying pan on medium heat, warm the oil for about 5 minutes. Do a test to see if the pan is hot enough by adding a sprinkle of water, to see if it sizzles.
Place each prepared filet (dipped in egg, flour, and then coconut mixture) into pan; the oil should surround the fish.
Cook 2-4 minutes per side (depending on thickness–if fish is thick, cook longer and slower), until the breading is golden brown.
Place the diced mango, 1/2 cup red onion, cilantro, and the juice of 1 fresh lime in a small bowl.
Serve the mango salsa on top of the fish, or with your favorite dipping sauce.