Open daily, 6 p.m. to midnight. BA, MC, V. Reservations. Prices: Main courses $9.50 to $14.50

I wonder where the Garden winters, and I wish it were Washington. Too often a restaurant is either pretty or efficient or clever or good, but seldom is it all four. At the Garden it is.

The beach is a place to feel outdoors even when you are indoors, so the Garden suits, its interior subdivided by a bamboo gazebo and garlanded with hanging greenery reflected in leaded glass dividers. The beach is also a place to relax, unbend rather than be officious or formal. Thus the servers at the Garden are casually dressed, friendly and gregarious; but they also understand the food that is being served and are able to describe it accurately and serve it gracefully.

Further, the beach is a place and summer is a time to eat seafood, fresh and light. Again appropriately, the Garden offers 13 seafood entrees along with its three veals, two ducks and roast strip steak. The appetizers, too, list 10 seafoods versus two pates, artichokes, snails and soup.

The first impression of the Garden, then, is that it is suitable. As an evening wears on, the impression is deepened; the restaurant has a distinctive personality, a quite attractive mien.

It is expensive. This is no hich seafood joint. Seafood appetizers climb to $7.50, most of them in the $4 to $6 range. The terrine maison - the only dish I found dull and in need of revamping - was $5.50, for no apparent good reason. Most main courses are over $10. But the price includes more than one would anticipate. First, there is the bread, hot, buttery homemade slices that are cousins to croissants. But even before that, one might well order a drink here; the orange joice is promised to be freshly squeezed. The wine list is small, but its choices are interesting and its prices fair.

On to appetizers, the Garden pate, at $3.75, is a better choice than the terrine maison; it is a soft, smooth duck liver pate of character. Several seafood combinations can be samples as appetizers, though they are also listed as entrees. The shellfish are sensitively cooked, their sauces creamy.

Next, a salad comes automatically. It is mixed tableside with a flourish, fresh and crisp, tossed with a fine shallot vinaigrette. Vegetables are equally conscientious, perhaps summer squash or cauliflower or hash brown potatoes.

An interesting preparation, and a highly successful one, is trout Prudhomme, the trout cooked on a bed of minced vegetables for seasoning, stuffed with shrimp and chunks of softshell crab. It is a proud ending for a fresh trout. Duck is also prepared uniquely, sauced with a thick, sweet melange of apples, raisins, cinnamon and apple brandy. It is a delicious foil for the crisp-skinned duck.

Dessert possibilities are appealing at the Garden, notably a flossy combination of cake, custard, fresh pineapple and whipped cream called Rita's Delight. But dessert is unnecessary, since you are brought a stunning bowl of fruit (melon wedges, grapes, oranges, apples, bananas, grapefruit halves) interspersed with dried apricots and foil-wrapped chocolate mints. It is unexpected, generous, and as delightful as a birthday present.

And so is the Garden, a gift to a beach vacation.