Firm-fleshed, thickly cut fish, such as tuna, salmon, swordfish, halibut, grouper, or sea bass, cook best on the grill. Shellfish, such as lobster, shrimp, scallops, oysters, and mussels, also benefit from a light charring on a grill.

Seafood for the Grill
When cut into chunks, hearty fish, along with whole shrimp and scallops, are also good for kabobs.

Use a hinged basket for delicate sole and trout fillets. Place the fillets on bed of sliced citrus to prevent from sticking to the grill rack.

Stuff whole fish with herbs, citrus slices, or other aromatics for extra flavor and moisture while grilling.

Grill salmon on a cedar plank for an intriguing, smoky note.

Shopping for Seafood
Whole fish should have clear eyes; bright, intact scales and skin; and red, moist gills. They should also be gutted, cleaned, and scaled before it’s placed in the display case. Fillets and steaks should look moist and bright, and have a fresh, clean scent.

Choose firm, sweet-smelling fresh shrimp that are still in the shell when possible. (Most "fresh" shrimp have been previously frozen on the fishing boat, then thawed.)

Look for creamy white or slightly pink scallops with a mild scent. The best are sold as "dry," meaning they have not been treated with a solution to help them absorb more water.

Purchase live lobsters—the feistier the better. Male lobsters will have slightly larger claws, while females have slightly bigger tails.

Oysters and mussels should have a mild, sweet smell, and their shells should be closed tightly and feel heavy with water. Never buy oysters or mussels that remain open when touched.

All seafood should be kept very cold, preferably on a bed of ice set over a perforated pan, until the moment it’s grilled.

Preparing Seafood for Grilling
Trim off excess skin from fish fillets or steaks and remove any small bones with needle-nose pliers.

Refresh frozen shrimp before cooking by soaking in cold salted water for 10 to 15 minutes; rinse well. Shell shrimp by pulling off the heads, if present. Carefully pull off the legs on the inside curve of the shrimp. Peel off the shell, beginning at the head end of the shrimp. Devein shrimp after shelling by cutting along the back of the shrimp with a small knife. Gently lift and scrape away the dark vein, if present, with the tip of the knife, then rinse the shrimp under cold running water. Drain the shrimp on paper towels before proceeding with the recipe.

Rinse scallops and, if present, remove the small tendon attached to the side.

Cut lobsters in half lengthwise, exposing the tail meat, and remove the grain sac and white intestinal veins.

Scrub oysters with a stiff brush and rinse well before shucking. Use a folded cloth to cushion the oyster in your palm and protect your hand from the shucking knife. To shuck, grasp the oyster so the flat top shell faces up. Holding an oyster knife in your other hand, insert its tip into the oyster's hinge. Twist the knife sharply to break the hinge. Run the knife carefully along the inside surface of the top shell, severing the muscle that grips it but being careful not to cut the oyster or to spill its liquor. Discard the top shell. Carefully cut the muscle under the oyster to loosen it from the shell.

Scrub the grit off the shells of fresh mussels with a stiff-bristled brush, then remove the beards, if needed, by pulling or cutting them off just before cooking. Discard any mussels that feel light, as they are likely dead, or any that are heavy with sand.

Testing Fish for Doneness
Fish is done when the tip of a small, sharp knife can easily separate the flesh into broad flakes. Unless you are deliberately cooking to rare or medium-rare, as with tuna, the fish should be still moist at its center and the flesh should be just opaque and easy to flake. If it is already flaking without being prodded, the fish is overdone.

Testing Shellfish for Doneness
Lobsters are done when their shells turn bright red and the flesh becomes creamy white with no trace of translucence.

Shrimp are done when the shells just turn bright and the flesh is just opaque. Take care not to overcook shrimp, which can become dry and rubbery.

Scallops should feel slightly firm when lightly pressed with your fingers, and the flesh should be moist and just opaque when done.

Oysters and mussels are done as soon as the shells pop open; always discard any that fail to open.