Heeding the call to "raft up," the kayakers draw near to share the moment they've all been waiting for. Their vessels - red, yellow, green, colorful in a kindergarten sort of way - bob and sway beneath stunning lavender clouds. The sun sinks from view.
"I don't think I've seen water reflect the pinkness of the sky like that," says Barbara Miller, a speech pathologist who spent a recent Saturday evening on the waters of eastern Baltimore County for a two-mile, two-hour tour. She savors one last taste of a horizon washed in fuchsia, then turns to paddle back to shore.
So ends another day of aquatic adventure on the Gunpowder River, Baltimore's water sports mecca.
For 15 years, the beach at Gunpowder Falls State Park's Hammerman Area has been a favorite spot for windsurfing. Surfers come from Baltimore, Virginia and New Jersey, to enjoy the breezes that funnel up the river from the Chesapeake Bay.
Some monitor wind conditions at their computers; an anemometer on the Gunpowder shore feeds real-time information to a Web site, www.iwindsurf.com.
"When you see a hurricane coming through, you always see four or five people here waiting for the 40-knot winds, while the rest of the city's all scared," says windsurfer Mark Raginsky, 40, of Columbia.
"It's just such a perfect venue, windwise, beachwise, no-jellyfishwise," says Hal Ashman, whose Ultimate Watersports company rents windsurfing boards, sailboats and kayaks from the park's shore. "It's not Hawaii, and it's not Greece, but it's a beautiful piece of water and we're lucky to have it."
But while windsurfing's popularity seems to have peaked about a decade ago, there's a new game in town. Says Ashman: "The last two seasons, the demand for kayaking has been insane."
Recalling the crowds on the Fourth of July, he says, "People were perfectly happy to put their name on a list and wait a couple of hours. I would never have believed that five years ago. I thought this was just a windsurfing place."
Like windsurfing, like in-line skating, like so many other fads and trends, kayaking's growing popularity seems to be an import from the West Coast.
"In Maryland, it's taken a while to catch on," says Joe Hohn, manager of the Timonium location of REI, a Seattle-based outdoors store chain. Now, he says, kayaks outsell canoes by as much as 3-to-1.
According to the National Sporting Goods Association, the number of participants in kayaking and rafting, while declining nationwide, nearly doubled in the mid-Atlantic area between 1995 and last year.
The appeal: Kayaking is only as strenuous as you want it to be, and you're close to the water in a way that power boating can never match. Some swear by the Gunpowder as a great place to experience the sport.
"It's very relaxing. I feel like I leave the world when I'm down here," says Noreen Honeycutt. She's 40, a psychotherapist who practices in Roland Park. "It is therapy down here."
Her fiance, Frank Orzolek (44, blond mustache, ponytail, looks at home on a beach), is still into windsurfing after all these years. But he succumbed to a new habit after Honeycutt bought him a kayak.
"I didn't want it, but I took it out here and took about 10 strokes. I was half a mile from shore. I said, 'What if I really got into it, dug this paddle into it?'" he says. "Now I love kayaking. ... I'm what you might call an evolved, old redneck powerboater."
The couple, along with Honeycutt's 19-year-old daughter and a longtime friend, spent much of Saturday at the park. On a day that starts warm and sunny, more than 100 people, including about 40 windsurfers, line the shores by early afternoon.
About 15 have come from as far away as Vienna, Va., where they work together at a management consulting company.
The teals and greens and reds of the flags on shore are matched by the colorful sails and kayaks on the river.
Beyond, on the far shore, the view includes the trees that cover rural areas of Aberdeen Proving Ground. The smell of charcoal and the lapping of gentle waves add to the easy-living summertime feel.
By midafternoon, threatening clouds chase many away. But Jeff Vise, a 37-year-old salesman from Aberdeen, arrives for a quick windsurfing session.
"It is," he says, "every bit as much fun as it looks."
Then, as the dark clouds skirt past to the north, about two dozen kayakers assemble for a sunset cruise.
Ultimate Watersports employee Ray Fusco provides a quick lesson in technique. (Hands not too far apart but not too close on the paddle, swivel the torso, reach wider with the paddle to turn.)
Most on the tour choose what Ashman calls "ultra-stable" kayaks, which seem nearly impossible to tip. Ashman hops into a sleeker, but more precarious sea kayak.
This flotilla of fun-seekers paddles away from the shore and veers north, past the children swimming at the park's beach and the waterfront homes of Oliver Beach. After a short while, Ashman stops to point out the hard-to-spot entrance to a hidden cove, where narrow water trails lead to herons and all manner of wildlife.
"It's one of the most beautiful places in Maryland," he tells the kayakers. "That's my secret. Use it or lose it."
Hint: The entrance is near where a line of white stones ends, and a marsh begins.
After about a mile of paddling on gentle water, Ashman directs the kayakers to raft up, or hold together in a pack.
Some, like Keith Lessner's party of four, are well-stocked for their excursion with cheese crackers, soda, beer and a jug of rum and pineapple juice.
"We know how to eat. I'm not sure about kayaking," Lessner says.
After a little while, the sun falls behind the trees and homes of Oliver Beach, casting that pink-purple shimmer across the water. On their way back, the kayakers pass the Saturday night get-togethers at the shore homes. A volleyball game rages in one yard.
As the kayaks pull to shore and darkness falls, Tiffany Penna, a 33-year-old sales consultant from Mount Washington, reflects on her evening on the water.
"Beautiful," she says.