A NIGHT OUT in Annapolis generally begins in the afternoon, or at least earlier than in most towns. That's partly because after a long, sun-soaked day on the Bay, sailors tend to be mighty thirsty and hungry.

It's also because even landlubbers enjoy sitting by the water, sipping cocktails, watching boats return to port and listening to halyards clang in the breeze. But perhaps the biggest reason is that there is a feeling of holiday in the air. Folks in Annapolis just don't feel guilty about sitting still and watching the sun drop behind the state Capitol. This truly is the land of the pleasant living.

As the sun sets, the streets around City Dock are teeming with visitors who window shop for the most appealing restaurant and bar -- an especially confusing task in restaurant- crowded Annapolis, and often a futile exercise on weekend nights if you had an early dinner in mind. Advance weekend dinner reservations are recommended, lest you be left wishing you made reservations back when you should have bought property in Annapolis -- 10 years ago.

"Saturday nights in the summer are really busy," agrees Gillian Johnson, a spokesman for Historic Inns of Annapolis, the corporation that operates several local historic landmarks, including the posh, 200-year-old Maryland Inn on Church Circle. Over the past decade, Annapolis has seen a sudden expansion of hotels and night spots.

"We're having a restaurant war," says Johnson, who notes that several more hotels, complete with their own nightclubs, are currently under construction. "We have a lot of restaurants, and I don't know if we can support them."

If several recent weekend visits are any indication, however, Johnson's worries may not seem well-founded. The town on the Severn River could support additional night spots and certainly another parking garage.

For now, Annapolis is hopping with a variety of night spots ranging from McGarvey's Saloon and Oyster Bar, an old-fashioned watering hole and eatery, to the sleek, chrome-and- blonde-wood Carrol's Creek Cafe across Spa Creek in the Eastport section of town.

The oldest tavern along the City Dock is Middleton Tavern, a huge, two-story red brick restaurant that has been feeding hungry sailors since 1750. A narrow outdoor cafe runs the width of the building, and trying to secure a table here on Saturday night is like trying to find a parking space on the other side of the sidewalk. It requires timing and luck -- mostly luck. Once you do, however, it is well worth the effort.

A couple of doors away is McGarvey's -- which, like the working skipjack moored at City Dock, bears its owner's grandmother's maiden name, Anna McGarvey. Built in 1871, the place was looking its age when former airline pilot Mike Ashford bought it in 1975. He restored the building, kept the original brick walls and tin ceiling, and installed an old-fashioned birch bar. Five years ago Ashford doubled the restaurant's size by turning the abandoned warehouse next door into a raw bar and two-level dining area.

Nearby at 26 Market Space is Riordan's, a restaurant better known as a Georgetown-style watering hole. With athletic jerseys and equipment decorating the walls, and sports often the topic of conversation at the bar, patrons aren't surprised to discover that former Washington Bullet Mike Riordan is a part owner.

Up Main Street is Fran O'Briens, the largest of dockside night spots, with a capacity for about 275. There is live dancing music on stage Monday through Saturday nights starting at 9, and on Sunday evenings a disc jockey spins top-40 hits. And, like the O'Briens in Rehoboth Beach, O'Briens in Annapolis attracts a wide slice of the demographic pie on the restaurant side, but is packed mostly with singles on the bar side.

Farther up Main Street at the King of France Tavern in the Maryland Inn, jazz fans can hear top-name national acts like Charlie Byrd, Herb Ellis and Jimmy Witherspoon. The cover is only $2 Sunday through Thursday nights and seldom tops $10 on weekends. The Ink Spots are appearing through Sunday evening.

If you're in the mood for a frozen margarita, head back to Armadillo's at the City Dock, where they are memorable. Along with the standard selection of steaks, burgers and seafood, the menu includes a good selection of Mexican dishes. At Armadillo's Upstairs, a $1 cover Thursday through Saturday nights gets you plenty of acoustic music, usually provided by Washington-based musicians.

Next door is Mum's, perfect for a frozen strawberry daiquiri among pleasure-boating friends, and, if you are lucky enough to get one of the window tables, perfect for City Dock people- watching.

Another good spot for crowd-Afterdeck, the Annapolis Hilton's dockside lounge reached by water or through the hotel on Compromise Street. This is possibly the only spot in town where those not wealthy enough to own a yacht can still feel smug watching some unfortunate captain struggle desperately to dock his 75-foot vessel without sinking it. Scenes like this may provide temporary relief to those anxious about not having accomplished goals set earlier in life -- or even earlier in the day.

Cross the bridge at the end of Compromise Street and you'll discover Eastport, a tiny peninsula marked by Spa Creek, the Severn River, Back Creek and night spots that, unlike downtown's, tend to have their own free parking lots. Among them is Jason's, formerly Spiro's, bought last year by Annapolis land developer James C. Foote, who gutted it and invested $1.2 million in renovation. Jason's, at 400 6th Street in a combination residental/business section, is now seeking approval of the zoning people to have live music and dancing. Until then, taped tunes from the '40s through '60s are on the sound system and mimeographed lists of Annapolis aldermen are on the bar, and there's a sports motif on the walls that leans toward local heroes who claimed their fame before 1969.

"We aren't trying to attract teeny boppers," says spokesman Rodney Calver. "We're aiming to be a family restaurant with an emphasis on younger professionals -- the 25-year-old and older bracket."

Down Severn Avenue, with a view back across Spa Creek to Annapolis, romantics will find Carrol's Creek Cafe, a sparkling new restaurant and bar specializing in Cajun cooking. A spacious wooden deck hanging above a sailboat marina provides a special view of skyline behind City Dock, particularly at happy- hour, when the sun is setting and the hors d'oeuvres are free.

Also along Severn Avenue is Marmadukes Pub, a local sailors' hangout where videotapes of the Wednesday night sailboat races are run nightly. On weekends, there is live music in the upstairs lounge.

Down another block in what was once a sailmaker's loft, the Chart House offers an excellent salad bar and some of the best seafood in town. Unfortunatly, telephone reservations are not taken, so arrive early. Dinner is served from 5 to 10; and until 11 on Friday and Saturday nights.

If your feet aren't killing you at the end of the day, put on your dancing shoes, hop in the car and head west on West Street. Here you'll find The Library, a restaurant with a second-story disco. Like the books on the shelves, The Library is a bit worn and tattered but the prices are right and there's live top-40 music.

If you'd rather put your dancing trust in a deejay, ride out of town on West Street to CJ's in Parole Station where there's dancing nightly and plenty of promotions like the "headphone singalong." If you're in the market for an upscale disco, pulsating with light, sound, and singles, sail on down to Margarita Maggies in the Plata Grande, near Annapolis Mall in Parole. This is the new, improved version of the flashy Beltsville disco. There is never a cover and almost always a line by nine. Jeez, just like home. SOME OTHER HOT SPOTS

GRADY'S -- 222 West Street. 301/263-6949. This small, 45-seat club will close during August for renovation but will reopen in early September with acoustic and swing groups. "Big Nite Out," a Philidelphia-based swing group is scheduled on September 6.

GARFIELD'S -- 73 Revell Highway (U.S. 50 east) in the Annapolis Terrace Motel complex. 301/974-1415. Live rock'n'roll Thursday through Saturday nights in '50s notty pine-style club named after actor John Garfield who sets the theme. Game room for pool sharks and darters. Cover $1-3.

HARRY BROWNE'S -- 66 State Circle. 301/263-4332. Piano bar from 9 to 1 nightly in new art deco lounge upstairs. Food served in dining room and in outdoor cafe.

HARBOUR HOUSE -- On the City Dock. 301/268-0771. A two-story restaurant complex that caters to the tourism trade and specializes in seafood and beef. The Harbour House restaurant is open from 11:30 a.m. to 10 p.m. everyday. The Terrace, an outdoor cafe overlooking the City Dock, serves dinner and lighter fare complete with classical music every night; perfect for eyeing the harbor, it's open May through October. Brendan's, a posh, mostly French restaurant named for the Irish patron saint of sailors, is below the Harbour House. Unlike most restaurants in town, it requires men to wear jackets. Classical piano music is performed during dinner, which is served Monday through Saturday. For reservations, call 301/268-4118.

MARINER'S WHARF -- 1993 Old Annapolis Blvd. 301/757-2424. Live Top 40 music, Friday and Saturday nights. Sunday brunch, $9.95. Seating for 100 on outdoor deck overlooking the Severn River and Annapolis. The Mariner's Wharf can be reached by boat.

O'LEARY'S SEAFOOD RESTAURANT & MARKET -- 310 Third Street, Eastport. 301/263-0884. High marks go to this small restaurant, the latest addition to a 40-year-old crab wholesale and retail market operation. Most tables are saved for walk-in customers, so only a limited amount of reservations are accepted. Dinner served until 11 Friday-Saturday; 10 on Sunday; and 10:30 Monday-Thursday. Local trivia: O'Leary's operates the northernmost crab picking facility in the United States.

YESTERYEAR'S -- 187 Annapolis Mall. 301/266-0877. Mixed seafarer and antique motif with large square bar.