When biologist Cameron Pratt leaves work, she doesn't join other motorists in rush-hour traffic. Instead, she boards a 20-foot boat and motors home over the choppy waters of the Coastal Bend region of Texas. She passes dolphins, sightseeing boats filled with tourists and small flocks of brown pelicans, finally mooring at a private dock on Harbor Island.

The home she shares with her husband, Rick Pratt, isn't your usual shoreline cottage or luxurious mansion with sweeping views. It's a house that stands on pilings next door to a 70-foot lighthouse on a private island that ranges up to 25 acres in size, depending on the tide.

"I love it here," Cameron says. "I'm a naturalist who gets to live in a place where I'm watching the rhythms of nature. . . . You're a part of nature, living out here. It's wilderness. Nothing's here that isn't supposed to be here. Everything's indigenous. It's just gorgeous."

Cameron, 46, and Rick, 56, are among a tiny handful of lighthouse caretakers in the nation. The small group is responsible for maintaining the romantic structures that symbolize solitude and strength — beacons that have slowly decreased in number over the years as computers and satellites ushered in more sophisticated methods of navigation.

The Pratts have served as live-in caretakers of the 145-year-old Aransas Pass Light Station, formerly known as Lydia Ann Lighthouse, for the past 17 years. They know their stuff. Rick has provided advice to authorities at the Texas Maritime Museum in Rockport. When museum officials recently built an addition that doubles as a lighthouse, Rick explained the Coast Guard requirements for a beacon.

Accessible only by boat and helicopter, the Pratts' rustic home gives them solitude, breathtaking sunrises and sunsets and the satisfaction of knowing they're keeping a piece of history alive.

But life at the lighthouse isn't always easy or quiet. Living in a historic waterfront building surrounded by natural beauty on an uninhabited island can be busy and laborious.

The lighthouse was built in 1856. Charles Butt, president of the H-E-B grocery store chain, bought the structure from a private owner in 1973. He then hired the Pratts in 1984 to refurbish and maintain the historical landmark.

The Pratts climb the spiral staircase in the 70-foot lighthouse every evening to turn on the main light that guides mariners in the Gulf of Mexico to Port Aransas. And they climb those 60 steps again every morning to turn it off. But there's plenty more to do.

Rick works about 12 hours a day. He replaces boards on the boardwalks. He maintains the two powerboats they use for trips to Port Aransas.

He repairs the saltwater toilet pumps. Patches the roof. Replaces rusting nails, nuts, bolts.

"It's a very hostile environment," Rick says. "We're surrounded by a corrosive fluid: saltwater. Literally, the sea is underneath the houses on high tides. It's very tough."

Acquiring new possessions means bringing them in by boat. That's not easy when the new possessions are furniture.

"Everything depends on us," Rick says. "Out here, you quickly learn the difference between what you need and what you want. . . . You don't run down to the corner store because you forgot something."

The Pratts also have frequent duties as hosts for visitors including the lighthouse owner and his guests. But the Pratts enjoy all the hard work.

"Your work is quite visible," Rick says. "And how many people get the chance to be a lighthouse keeper?"

The Pratts don't watch television, except for occasional movies on video.

There's better entertainment when they climb to the top of the lighthouse.

"It's a wonderful place to watch a storm come in," Cameron says. "A lot of energy. It's kind of scary fun, watching a norther come in from way across the marsh."

The black mangrove bushes around the lighthouse sometimes attract thousands of fluttering white butterflies. "This place is just dancing with light when that happens," Rick says.

"We watch the dolphins come up the creek during low tide, and they'll herd the fish into the creek," Rick says. "Then they roll, and it causes big waves, which wash fish on the bank — little bait fish — and they turn around and gobble them up as they come flopping down the bank. It's incredible. It's a feeding strategy I never heard of."

They have old friends — a bird known as a kingfisher that always perches in a certain spot, and peregrine falcons that nest on the lighthouse tower.

"We've had flights of hummingbirds that come through here, as many as 500 or 600 in a day," Rick says. "You sit on the porch and watch them go by at an incredible rate of speed. . . . The natural environment is one that is very nurturing to us."

The Pratts feel real pride in what Rick calls "the biggest porch light on the coast." They end each day with pomp: Rick Pratt plays bagpipes while Cameron lowers the flags that fly in front of the lighthouse.

"Lighthouses hold this mystical fascination for people. I'm in that group, I guess," Rick says. "And this is an island — a literal, real island. When you're here, no one else is here. It's an absolutely beautiful setting. There's never been an ugly sunset. Dolphins are our nearest neighbors. . . . There's a special peace to this place."