ANNAPOLIS -- On Wednesday nights in Annapolis, the crowd is packed in elbow-to-elbow at Marmaduke's, a popular pub a block from Spa Creek. Small groups of men and women wearing khaki shorts and tanned faces stare raptly at a television set hung from the ceiling by the bar. Occasionally, a burst of laughter or a triumphant cheer is directed at the soundless images on the screen.

At any other watering hole or on any other night at this one, Cal Ripken and the Orioles would be providing the evening's entertainment. But in a Hump Day tradition that is peculiarly Annapolitan, these regulars have come to watch themselves on a jumpy videotape shot hours earlier as they raised, trimmed and took down sails while racing boats on the Chesapeake Bay.

It will never make the "Wide World of Sports," but the post-race replay is one of the traditions that has grown up around the Wednesday night sailboat races sponsored by the Annapolis Yacht Club. Completing its 37th year tonight, the April-to-August series has made an indelible mark on the culture of this seafaring city, no small achievement in a place that bills itself as the Sailing Capital of the United States.

So much an institution have the mid-week races become that they affect the way business is conducted here. Since the first boats move off the starting line at 6:25 and an hour or so of preparation is needed to get the vessels ready, sailors who work in Baltimore or Washington usually leave their jobs early to get to the race course on time. Longtime residents of Annapolis know that in summer, Wednesday afternoon is not the time to buy a house, seek legal advice, schedule a doctor's appointment or apply for a loan.

"No one expects to do business on a Wednesday night, but I have gotten a lot of business through sailing," said Margaret Templeton, a mortgage banker who crews on a boat called Inside Scoop.

As far as marketing strategies go, the money Maramaduke's invests in its Official Video Boat makes sense considering that there are probably 900 adults competing on the water each week and another several hundred spectators. The 120 boats entered in the series are worth at least $8.5 million combined.

"This is like bowling night. They wouldn't miss it for anything," said Jim Mumper, owner of the 31-foot Diamond in the Rough.

"Only the bowling balls are a lot more expensive," said Dan Breen, 43, a paper products salesman.

Participants say the "Wednesday nights" are an invigorating respite from humid city streets that help break up their weekly routine and prepare them for more intense weekend races. They look forward to the stirring sight of dozens of boats parading toward the starting line near the mouth of the Severn River, the strategy of finding the pockets of good air to propel them forward, the rush of raising the colorful spinnaker sails, the challenge of timing their turns around the markers just right.

Although described as a low-key, family-style event, the series draws some of the most experienced sailors in the region, including several veterans of America's Cup races. One sailor flies in from Hartford almost every week and another drives in from Delaware.

On one recent night, the 11-member crew on the 43-foot Fun logged a total of 295 years of sailing experience.

The boat's owner, Tom Closs Sr., accounted for 70 of them.

New boat owners with little sailing time under their belts often recruit the services of "rock stars" -- people who work in the sail lofts or boat yards where the boat owner is known to be a good customer -- to improve their chances of winning a trophy.

"When you blow $200,000 to $300,000 on a boat, yeah, it's a gentleman's sport, but they want to win," said Ted Joseph, a McLean real estate agent who makes the weekly trek.

By 8:30, it is all over.

The sailors are back at their piers, beers in hand, indulging what seems to be an endless appetite for rehashing minute details of their last races and reliving their errors.

Joined by a love of sailing, they seem reluctant to talk about anything else and a non-sailor is easily lost in the jargon of their sport.

In other words, in Annapolis on Wednesday's, be prepared to talk jib.