Restaurants : LANDING A BIG ONE : At the Water Grill, the Fish Is Fresh, the Desserts Luscious, the Service Insouciant

Here’s the story: A major-league seafood restaurant, the Water Grill, recently opened in fish-starved downtown Los Angeles. Expect to find it moderately busy at dinner (which it makes a point of serving as early as 4:30 on Thursdays and Sundays for theater matinee-goers) and packed to the grills at lunch. But where is it?

If you believe the people who answer the phone, the address is 523 Grand Ave. They probably think this for the silly reason that the street entrance, which is on Grand, has the number 523 etched above it. Don’t believe it: That door is on the east, or even-numbered, side of Grand. The number actually refers to the address of the entire building, the entrance to which is around the corner on 6th Street.

I wouldn’t go into so much detail on this if I hadn’t once spent 10 minutes in the Twilight Zone searching the west side of Grand for the nonexistent address of a restaurant whose name, now that I thought about it, made it sound as if the specialty of the house was grilled water. So just remember: 6th and Grand, east side of the street. We’ll say no more about it.

The Water Grill has the wood-paneled ambience of an old-time businessmen’s lunch place, complete with a long bar in the middle of the room. The effect is lightened with mirrors and glass, contrasting with the wackiness of the room’s colorful, demented murals with underwater motifs. On my first visit, the management gave away mechanical fishies for its customers’ bathtubs.

But the place takes its seafood seriously. Anyone who has eaten at other restaurants owned by University Restaurant Group, such as Ocean Avenue Seafood in Santa Monica or Pine Street Fish Restaurant in Long Beach, will recognize the style. The top of the menu lists the day’s catch, usually about 40 kinds of fish and shellfish, in boldface type, so if you have your mouth set for periwinkles, Coromandel oysters or Idaho catfish, you can tell at a glance whether to leave it set that way. Waiters insist that the dishes spelled out beneath are mere suggestions, but the menu is so large and varied, I doubt many people make special requests.

The appetizer department promotes the “fruits of the sea” platter, a huge display of shellfish on ice somewhat grandly known as the Signature Dish. Count on five or six kinds of oysters (say, Canadian malpeque, Fanny Bay, Chiloe, Kumamoto and New Zealand rock)--all very fresh and good--plus clams, some Canadian spot prawns, excellent black mussels from Prince Edward Island, pink scallops complete with roe (pretty to look at, though not necessarily the most memorable to taste) and either a sea urchin, tasting as if a particularly damp ocean breeze had entered your mouth, or some lobster. They might also slip you a few little sea snails that show what escargots would taste like if they lived in the ocean rather than your garden.

The Signature is the budget buster of the menu, running $33.50 for two people (the minimum number); no other appetizer costs more than $13. Of course, you might prefer something smaller for an appetizer; something like the warm scallop-and-spinach salad, with its plush scallops and vigorous bacon-studded vinaigrette dressing, probably suits the purpose better. I’d treat the multicolored tower of tangled vegetable threads on top of it as an amusing ornament rather than part of the salad.

The Dungeness crab cake, conceived along the lines of a crab burger, has a crunchy browned skin and a smart beurre blanc sauce dosed with rosemary and tomato (a waiter mysteriously referred to it as “our gazpacho beurre blanc “) . Excellent smoked sturgeon and salmon come on a warm potato pancake with sour cream and caviar at one end. The clam chowder ought to be listed as clam-bacon chowder--we’re talking major bacon action--but shows class in its preparation: The little potato cubes keep their texture beautifully.

In fact, just about everything keeps to a high standard. I don’t see the point of pink grapefruit sections in lobster cocktail, and some of the steamed mussels might seem fresher than others (nice cream-and-chive broth, though). Only one appetizer has puzzled me: the marinated Spanish mackerel, a revelation in its way--we rarely get mackerel this fresh--but $8 is a little steep for two tiny chunks of fish.

The Water Grill obviously works hard to get top-notch seafood. You don’t find many restaurants serving Arctic char--a delicate and refined cousin of salmon--or Copper River salmon, a particularly clean- and sweet-flavored salmon unfortunately available only during a short season. And the Water Grill’s kitchen doesn’t go crazy in the preparation (though monkfish osso buco is a quite absurd idea, no matter how nice the osso buco sauce).

Sea bass with roasted potatoes shows the Water Grill at its best. The fresh, sweet fish is tiled with potato slices--as if it were armored in browned potato chips--and a flotilla of cockles, little smoky-tasting sea snails, surrounds it.

The menu is organized by region of origin of the fish, with preparations supposedly characteristic of the regions. That sea bass dish was California-coast style. In the Gulf of Mexico department, you find baked amberjack--like a rich, fresh tuna--with fried plantains and refried beans, and blackened thresher shark (New Orleans being on the Gulf, you understand), with a pleasant, though bogus, remoulade sauce (in this case, mayonnaise spiked with red pepper). The fact that petrale sole with hazelnuts was a Pacific Northwest dish and ono with a ginger-tomato chutney was Hawaiian came as news to me.

The seafood focus may seem a little obsessive, but there’s a bit of land-based stuff. The same wonderfully loud apple-smoked bacon that dominates the clam chowder also dominates the trout fillet. I suppose you should remove part of the bacon in order to let the trout flavor come through, but you’d need an iron will to deny yourself this bacon.

And the desserts are strictly terra firma, a lot better than you might expect in a seafood restaurant. A shortcake with seasonal fruit comes with a subtle maple-flavored cream sauce; the chocolate pudding, with shards of sheet chocolate sticking out of it, is a daringly simple, old-fashioned pudding--without skin. You can’t have a dessert list these days without a serious chocolate blowout like the chocolate torte, but it’s stylishly dished up with enamel-like streaks of chocolate and caramel sauce on one side of the plate.

When the waiter brings the parfait of blackberries and white chocolate with two long almond-studded biscotti sticking out of it, looking like bread sticks, he may say, “Here’s Bugs Bunny.” But the last laugh goes to seafood: complimentary chocolates shaped like shellfish.

Water Grill, 523 W. 6th St., Los Angeles; (213) 891-0900 . Open for lunch Monday through Friday, for dinner nightly. Full bar. Valet parking in underground lot. All major credit cards accepted. Dinner for two, food only, $37-$80.