Summer isn't subtle at the beach. One day, it's sleepy spring here, with long stretches of empty shore, and then Memorial Day weekend hits and it's so crowded that Melissa Clink doesn't set foot in the sand, even though she lives 1 1/2 blocks away.

"I like my space," she admits, noting that there is little room to move between the season's crush of bright umbrellas and prone sunbathers in Rehoboth Beach. But for Clink and many others who live year-round in resort towns outside Washington, summer is no time for relaxing anyway.

They rev up for the weeks when out-of-towners arrive to wind down.

In Clink's case, this happens because she owns a bed-and-breakfast inn and tends to scores of guests during summer months -- baking muffins, cleaning rooms, organizing backyard cookouts. Amid the rhythms of summer, though, Memorial Day stands out.

"It's a total zoo," she says cheerily. "It's like the bachelor party before the wedding. It's the k ickoff of summer, and it doesn't matter what the weather is."

Three weeks before calendars mark summer's official beginning, Memorial Day weekend brings its traditions to the beach. With sunshine expected and hotels bulging, the population along the Delaware and Maryland shorelines will swell remarkably.

Ocean City, Md., will explode from about 25,000 people to more than 200,000. Rehoboth Beach, which counted 1,234 people in the last census, will become a bustling city of as many as 50,000. Dewey Beach, Del., will balloon from 350 to 35,000.

"It's probably our best weekend of the summer," said Allen Fasnacht, who operates the Rehoboth boardwalk's 18-ride Funland with three generations of his extended family and a small army of teenagers.

Farther south, in Ocean City, though, they've already had a dress rehearsal. Last weekend, 3,000 classic cars came to town, drawing crowds that filled most hotels.

To see how resort-town lives spin faster with the arrival of summer, consider the job of a local chef: Quiet 40-hour weeks give way to 100-hour weeks of feed, feed, feed. The pay isn't any higher if you're on salary, as many chefs are. There's more food to order -- 20 pounds of chicken that lasts two days instead of two weeks -- and more dishes for the kitchen.

"It's harder to please the summer people than it is to please the locals," says Dan Chauncey, 35, chef at Duffy's Love Shack, a Caribbean-themed restaurant in Ocean City.

spring and fall attract an increasing number of shore-bound tourists, summer is so much the main act in Rehoboth Beach, and it has been preceded by all manner of primp and preparation.

In Rehoboth Beach, which boasts that it is "the nation's summer capital," restaurants unveiled new menus. Stores brought in new merchandise. The one-mile boardwalk has come to life, with its french fry joints, salt-water taffy stands and beach ball displays.

Nearby, on Delaware Avenue, Clink planted flowers, assembled a new gas grill, bought a new flag, discarded a couch and waited on an electrician to wire her porch for ceiling fans. "If it doesn't get done now, it won't get done this summer," said Clink, 44, owner of At Melissa's and a former resident of Northern Virginia.

Less welcome across town were parking meters -- hundreds of them -- reinstalled in time for the influx. After a winter of free parking, the city demanded its first quarters Friday.

Police Chief Creig W. Doyle hired 29 summer officers to join the department's year-round force of 16 and pledged another year of "zero tolerance" for urinating in public, littering and making too much noise. Largely as a result of that policy, last year's arrests climbed by 18 percent, he said.

"We're not trying to be the Gestapo here," he said. "We want everyone to have a reasonably good time but respect everyone else's right to have a good night's sleep."

On First Street, Bob Plunkett took in the seasonal spruce-up as he assembled a raspberry-colored beach cruiser at his shop, Bob's Bike Rental. "Summer's here," he observed contentedly, his well-lined hands turning a wrench.

An inevitable result, Plunkett conceded, was traffic. The worst backups may be just outside Rehoboth Beach, along the increasingly developed Route 1 corridor, where bumper-to-bumper tie-ups are common in summer.

"People go nuts," he said.

The visitor boom changes the daily rituals of people who make their homes at the shore. The excitement of the summer, they welcome. The lines, they try to avoid.

Steve Elkins, a leader in Rehoboth's large gay community, said he and his partner, Murray Archibald, will begin shopping at a pricier grocery in town rather than battling the traffic to a supermarket on Route 1. "It costs more," he said, "but it's worth it."

At Browseabout Books & Cafe, where many locals pick up coffee and a paper in the morning, Dick Evans, 64, vowed to avoid all midday trips to the supermarket. From now on, such excursions would be made at dawn, he said.

"The roosters and I will be out there, gathering corn," he said with a chuckle.

Evans and his friend, Ed Henriksen, 69, typically meet mornings with a dozen others for a cup of organic brew and some leisurely chatter -- about golf, horse racing and the foibles of President Clinton. This, they said, would not change.

"The whole thing is attitude. You have to learn to live with it," Henriksen said.

Duncan Monroe, who owns the Cotton Club clothing store with his wife, Debbie, said that he hears a few residents complain about the ruckus, saying, "This isn't what I moved here for." His retort, he said, is, "Imagine what it's like now where you came from."

In spite of complaints, many locals say the adjustments are not overwhelming.

Joan Epstein, who has vacationed in the area more than 30 years and is the mother of Kathie Lee Gifford, said she often bikes at sunrise to get a quiet moment in the noisy months. "You have it all to yourself at that hour," she said.

Epstein said she would not dare complain about tourists. "Crowds are a part of beach life," she said. "They keep this town going."

Joan and Jim Sperry said they avoid Rehoboth restaurants on weekends, when lines are long and waiters are hurried. They eat out on summer weekdays instead. As for the tourists, Jim said, "We were them for a lot of years."

Staff writer Linda Perlstein contributed to this report from Ocean City.

CAPTION: Chris Luka, of Chambersburg, Pa., spends the first day of Memorial Day weekend up to his neck in sand in Ocean City, Md. With the influx of tourists, the town of 25,000 people is expected to expand to more than 200,000.

CAPTION: Crowds fill the boardwalk at Ocean City at the beginning of the beach's hot season. In beach towns, many locals change their routine to avoid the crowds.

CAPTION: Volleyball games, sunbathers and umbrellas cover the beach at Ocean City, as restaurants, hotels and other tourist-driven establishments along the seaside gear up for the not-so-lazy days of summer.