PERHAPS THE delicacy offish accounts for it being too often overlooked and neglected as outdoor fare; but both fin fish and shellfish are excleent candidates for outdoor cooking. Certainly fisherman have never hesitated to cook just-caught fish at the water's edge. The delicacy requires intelligent preparation, but that is true for cooking indoors as well as outdoors. The methods of cooking can range from charcoal grilling to poaching, steaming and frying, from a solitary fish fry to a clambake for a crowd.

When cooking fish outdoors, simplicity should be kept in mind. While some strongly flavored fish is enhanced by seasonings, a very subtly flavored fish should not be overwhelmed with sauces. As in all fish cookery, consideration should be given to the type of fish -- fat or lean. A fish with a high fat content, for example, will require less basting with butter than a fish and shellfish over coals is one of the simplest ways to prepare it outdoors. The Indians used the simplest method of all: They would thread a cleaned, but unscaled fish on a sassafras twig and cook it over a hot fire. When the fish was done, they simply peeled it and ate it.

Our methods are slightly more sophisticated, but the intent is the same: to cook absolutely fresh fish quickly in order to enjoy maximum flavor and delicacy. The most common error in cooking fish is overcooking; and when cooking over charcoal, careful attention must be paid to avoid this travesty. For simple grilling, small, cleaned fish may be given a light coat of oil and placed over the coals. A rule of thumb for cooking all fish outdoors is to measure the thickest part of the fish from sticking to the grill, but careful turning is required to avoid tearing the fish. Large fish may necessitate a long-handled fish rack or a casing of clean screen; however, only the largest fish will require special equipment in order to turn it. When preparing fish fillet for outdoor cooking, remember to leave the skin on one side; this keep the filet together and makes it easier to turn. Often it is unnecessary to turn a fillet, as it will cook through very quickly. There are many sauces appropriate for basting fish, but some of the easiest are clam juice, a light fish (or even chicken) broth, melted butter and lemon juice. When preparing a large fillet or large, whole fish for charcoaling, make several shallow, diagonal cuts across the fish, to prevent puckering, and to allow basting sauce to penetrate and flavor the flesh.

In addition to plain grilling, fish can be placed in aluminum foil packets for baking. Baking fish outdoors is easier if your grill has a cover. Also, a long-handled camp skillet may be placed over coals for frying fish. Fish rolled in cornmeal and fried outdoors over a hot fire is a traditional treat. This is best done on a permanent-structure barbecue grill, and never on a wobbly or makeshift arrangement. Frying fish outdoors requires careful attention and proper disposal of the hot oil once the fish is done. Extreme care should be taken when dealing with hot oil, and long-handled tongs and asbestos mittens should be used. Although it is said that a clambake is ready when the bake master can no longer stand, this is definitely not the case at a fish fry.Sobriety and the cook must be partners.

If fish is to be transported to an outdoor cooking site, remember that it must be kept very cold to prevent spoilage. An insulated cooler with ice is ideal for transporting fish. Never put fish fillets in ice water; rather, put the fillets in plastic bags, seal the bags and then put the bags on ice. Always remember that fish is highly perishable, and plan to cook only the amount that will be needed. Leftover fish that has been cooked and then left unrefrigerated should be thrown away.

Outdoor fish cookery does not end with charcoaled fish. ywhy not take the steam pot outside for a feast of crabs, clams or lobster . . . with corn thrown in for good measure? Getting out of the heat of the kitchen is as easy as putting that steamer over coals outside, where the breezes are. CHARCOALED RED SNAPPER (On large croaker, etc.) (4 servings) 1/4 cup lemon juice 1 bup butter, melted Salt and pepper 1 large red snapper, cleaned, head removed Lemon wedges and parsley, for garnish

Prepare charcoal for grilling. Blend together lemon juice, butter and seasonings. Brush fish all over with butter sauce and wrap in aluminum foil and place over coals. Open foil frequently and baste fish with butter saice. Grill about 15 to 20 minutes, or until done. If in thickest part, and allow 10 minutes cooking time per inch. When fish is done, garnish with lemon wedges and parsley. STUFFED CRABS (6 servings) 1 pound crabmeat Salt, pepper, capers, to taste 1 pimiento, diced 1 teaspoon melted butter Mayonnaise 1 whole garlic clove Olive oil Garlic dill pickles, for garnish

Mis crabmeat with salt, pepper and capers to taste. Add pimiento melted butter and enough mayonnaise to moisten. Rub 6 crab shells with garlic and olive oil. Heap mixture in shells, wrap shells in aluminum foil and heat over coals -- about 20 to 25 minutes. Garnish with garlic dill pickles. GRILLED SWORDFISH

Imx together equal parts mayonnaise and dijon mustand.Coat one side of swordfish steak (1 1/2 to 2 inches thick) with mixture and place that side down on grill over coals. Coat the top with mixture. Broil about 15 minutes per pound, turning and basting as necessary. Do not overcook. Fish will be firm and moist, and will flake easily when done. CALIFORNIA BARBECUE SAUCE FOR FISH (Makes 2 1/2 to 3 cups) 1/4 cup wine vinegar 3/4 cup sherry (not too sweet) 3/4 cup chicken broth 1/2 teaspoon powdered ginger 1 clove garlic, crushed 2 tablespoons catsup or chili sauce 1/4 teaspoon paprika 1/4 cup soy sauce 1 teaspoon worcestershire sauce 1/2 cup cooking oil

Heat ingredients together. When cooking fish or grill, baste with this warm sauce. (Flounder, dolphin or other fish)

Soak fillets in lemon juice 15 to 20 minutes. Grill, basting with melted butter, about 15 minutes per pound. This is good severed with hollandaise sauce. BASTING SAUCE FOR FILLETS

Mix butter, lemon juice, anchovy past to taste; add a dash of vermouth. Baste fish with sauce when grilling. FISH GRILLED IN CORN HUSKS (Serve 2 fish per person)

Use small, cleaned fish (weakfish, perch, bass, etc.) Brush with melted butter and lemon juice, and sprinkle inside and out with salt and pepper. Wrap each fish in waxed paper, then in cleaned corn husks, or aluminum foil, or cabbage leaves. Tie with string and place on grill. Cook about 15 minutes per pound, or until corn husks are charred and fish is tender. PINE BARK STEW (6 or more servings) Few slices salt pork 1/2 cup minced shallots 6 peeled sliced potatoes 1 quart hot water Salt, pepper and curry powder, to taste 10 fish fillets 6 sliced onions

In a kettle over coals, fry salt pork, drain and set aside. Saute shallots and sliced potatoes. Add hot water, salt, pepper and, if desired, curry powder to taste. Let simmer a few minutes; add fish fillets. (Freshwater fish preferred for this dish.) Add sliced onions. Simmer about 1 hour over coals of pine bark and hickory wood. (The pine bark gives a slow heat.) If unable to use these traditional fuels, substitute charcoal, but be careful the fire doesn't get too hot. The stew has to simmer gently. CHARCOAL BROILED LOBSTER 1 to 2 pounds lobster per person Plenty of butter 1/2 cup lemon juice

Place split and cleaned lobster shell side down, on grill over red-hot fire. Brush flesh with melted butter and sprinkle with lemon juice. Turn fast, and broil about 6 minutes. Turn up again, brush with butter and check for doneness. Flesh should separate easily when done. Serve with the rest of the melted butter and lemon juice. MUSTARD-BROILED SPANISH MACKEREL (6 servings) 1 cup prepared mustard 1 cup scallions, finely chopped 4 tablespoons vegetable oil 2 tablespoons worcestershire sauce Salt and pepper 6 fillets mackerel (or other fish) Scallions, for garnish

Mix all ingredients except fillets, and use to baste fish when grilling over charcoal. Turn fish carefully, baste frequently, until done. (Average fillet will take about 10 minutes.) Garnish with whole scallions. APPLE SHRIMP (2 servings) 1 pound raw shrimp, peeled and cleaned Sliced apples, pecans and butter, to taste

Peel raw shrimp. Place in foil with sliced apples, pecans and butter to taste. Close foil and cook for about 10 minutes over coals. Time will vary according to size of shrimp and thickness of sliced apples. (Apples should be just tender.) LOUISIANA BARBECUED FISH (6 servings) Salt and pepper 2 red snappers, trout or other firm, good-sized fish, about 2 pounds each, cleaned but left whole. 1 stick butter 3 tablespoons grated onion 2 tablespoons parsley, chopped 2 tablespoons worcestershire sauce 2 dashes hot pepper sauce Juice of 2 lemons

Salt and pepper fish. Place on sheet of heavy foil. Melt butter and make sauce with remaining ingredients. Pour sauce over fish. Seal foil, making sure there is no leakage. Place on grill. Turn every 20 minutes, being careful not to puncture foil. Cook about 1 1/2 hours. Remove from foil and carefully place fish on grill, and cook about 10 minutes per side, basting with sauce from packet. BARBECUED BLUEFISH (8 to 10 servings) 1 bluefish, 8 to 10 pounds, or larger Vegetable oil 1 1/2 cups sour cream 1/2 cup mayonnaise 1 tablespoon prepared horseradish 1 tablespoon lemon juice 4 tablespoons capers 4 tablespoons minced dill White pepper 1 cherry tomato Lemon slices, for garnish

This is a cold dish, served in the manner of cold poached salmon. It is best cooked a day ahead and well chilled. Dress the fish, leaving head and tail intact. Wipe entire fish with vegetable oil and place ona grill over low charcoal fire. Use a covered charcoal cooker. The fire should be at least 10 inches from the fish. Depending on heat and size of fish, it will require about 45 minutes to an hour or more, as the fish should be cooked slowly. Add wet hickory chips at intervals to maintain smoke. Remove the bluefish from grill with large spatulas, retaining its whole shape, and arrange on serving platter. When cool, carefully peel off the skin, but do not remove the underlying dark meat (as in salmon preparation). Refrigerate overnight, or at least 6 hours, to firm.

Before serving, blend the sour cream, mayonnaise, horseradish, lemon juice, capers and dill. Season with white pepper to taste. Spread this mixture evenly over the body of the fish with the flat edge of a knife. Substitute a cherry tomato for the eye, and decorate the fish with thin lemon slices. Keep cold until ready for the table.