The triple-seven wedding blitz was part phenomenon, part marketing masterpiece. Chapels offered special "777" packages, extended their hours and spruced up their digs with balloons, flowers and banners. Casinos planned mass weddings and added special venues. One created the must-have photo opportunity: an underwater wedding in a 117,000-gallon fish tank. A couple in full diving gear held up "I Do" signs for the cameras.

"We're lucky people, and we knew today would be a lucky day," said Melisha Laura, after renewing her vows to her husband Ricardo Laura at the Silverado Casino Lodge. Ricardo, a Las Vegas police officer, said he survived seven gunshot wounds in February.

"I always believed in luck; I just didn't know seven was my number," he said.

The Clark County marriage bureau issued more than 1,600 marriage licenses on Friday, about four times the number of a typical Friday. The line of betrothed snaked down the sidewalk, with the wait in the 114-degree heat stretching five hours. About half a dozen people passed out in the desert sun, leading county officials to move the line inside on Saturday.

Many said they chose the date for its long-held, though hard to trace, lucky reputation. Three sevens is usually a jackpot on a slot machine. A seven can be lucky in craps. Some people cited biblical associations.

"It means finalization and completion in the Bible," said Lugretha Cain, 50, of San Diego. Cain came to Las Vegas to marry 47-year-old Terry Parker, a man she has known since she worked in a high school clerk's office 30 years ago, when he was a student there. The couple recently reunited.

Paul and Monica Gunderson said the date chose them. He closed his eyes and pointed to a calendar. His finger landed on July 7, 2007 — roughly a month since he had met Monica at a bar where her blind date had stood her up.

"I've always been very lucky, she's never been lucky. We're going to balance each other out," Gunderson, 29, said decked out in a turquoise golf shirt matching his bride's turquoise bustier.

The nuptial rush put Las Vegas' color on full display. Brides dressed in miniskirts, full-length sateen gowns and couture. Grooms were seen in flip-flops, tuxedos and tuxedo T-shirts. Elvis sightings were periodic.

David Heilman and Charlene Jimenez were the ones who took the plunge in scuba gear. The couple won an underwater wedding at the Silverton casino as part of a radio contest.

The couple vowed not to enter into marriage "lightly, but soberly, with the fear of God," in front of a cast of witnesses, including family, friends, gamblers in the casino, two divers dressed as mermaids, several stingrays, six species of sharks and a porcupine puffer.

But even in a town that specializes in mass-producing once-in-a-lifetime experiences, there were glitches.

Limousines pulling in and out of chapels on Las Vegas Boulevard created small traffic jams. Red-faced bridal parties lined up outside chapels, fanning themselves and seeking shade under the eaves. Flustered employees were forced to holler out names like butchers calling out numbers for the next in line.

"It's crazy," said Diana Krasinki, 21, as she waited in the sun for her cousin's wedding at The Garden of Love chapel. It was an hour and a half behind schedule. "I'm not sure this is what they wanted. I'd rather do it on a beach in Santa Barbara."

Chapel manager Barbara Ludwig said Garden of Love was on track to marry 400 couples on Saturday, up from about 120 on a typical Saturday. It would not turn anyone away, she said.

Freed's Bakery couldn't make the same promise. It had to stop taking orders three weeks ago for its special "777" wedding cake — a three-tiered, $500-tribute to Las Vegas, complete with a tier designed as a die.

Max Freed, the general manager of the bakery, said he enlisted the help of the whole Freed family to complete the orders, a measure usually reserved for the holiday season.