Because most fish contain relatively little fat, marinating or brushing lightly with oil before placing on a grill is also recommended. This maintains moisture inside the seafood and prevents it from sticking to the grill. To keep the fish from sticking to the grill, oil the grate before adding the fish. Marinate the steaks, or lightly brush with oil. Place directly on the grill and cook for 5-7 minutes, or until cooked.
Fish is cooked when it turns from translucent to opaque in the center.
Fish fillets are more fragile than steaks. To prevent them from falling apart during cooking, the should be carefully cooked in a grilling rack or in foil. Fillets with the skin left on one side can be cooked directly on the grill. Lightly oil the grill and fish. Cook until done, basting frequently.