Seafood should be cooked over medium hot coals. Baste fish with flavored butter or marinade frequently during cooking. Bottled salad dressings work great but avoid overmarinating fish. Also, white-fleshed fish is delicate in flavor, so overmarinating can overwhelm it. Check fish often, removing as soon as it is translucent in center.
Fish is done when opaque and tender, easily flaking with fork.
Take care not to overcook.