She's elbow-deep in a hole she has dug in the sand. The Gulf of Mexico rolling onto the beach about 10 yards behind her is obligingly filling the pit with saltwater _ the more deeply she paws into the sand, the more quickly the water seeps in.

Sneak a look at her feet as she works. The soles are caked with Padre's light-brown grains, and grit clings to every toe. Lucinda Wierenga, an award-winning international competitor in sand sculpture and a teacher of the moist art, lives up to her nickname.

"I always leave a trail where I go," she says.

One of 100 or so professional sand sculptors in the U.S. and Canada, she began giving sand-castle classes 25 years ago.

On South Padre Island, she's a partner in Sons of the Beach, along with fellow sculptor-teacher "Amazin'" Walter McDonald.

"When I started doing lessons, I'd never heard of anyone doing it. I made it up," Sandy says.

She leans into her hole, her wrists cocked toward her like the bucket on a backhoe, and pulls a brick-size handful of dripping wet sand toward her. Then, with a quick movement, she plops the blob onto a tower-in-progress. It forms a burger-size patty that she settles with one hand before running her fingers around the edges.

Her "flip, jiggle, tuck" technique is the secret to getting height, she says. To get the sand patties to stick, you have to perfect that one-hand jiggle.

"What I'm not doing," she says, "is pounding, packing, pressing, patting, pushing or pummeling _ the naughty P words."

If she seems to have a gift for vocabulary, consider that she's a former high-school English teacher.

The Gulf breeze toys with her shoulder-length, salt-and-pepper hair as she declares the nascent tower tall enough. It's a ragged, upright column of sand crisscrossed with slender snakes of grit that ran from blobs and congealed.

It's not pretty, she admits. "That's where the carving comes in _ what I call the fun part."

Her No. 1 tool is a pastry knife with the tip cut off. "I do probably 90 percent of my carving with this. The offset handle lets you get close to the sculpture without your hand getting in the way."

She and her partner, Walter, designed the half-dozen other tools she uses. At the end of pencil-like handles are 50-cent-size, stainless-steel shapes: big and skinny squares, an arrowhead, a tiny trowel, a loop and a hollow U.

She sells the utensils in sets (about $40) but says tools don't have to be fancy. Any pliant metal _ bobby pins, paper clips, twist ties _ will do. A McDonald's plastic knife can sub for the pastry knife, she says. A paper straw can blow sand chaff from crevices.

She adds details from the top down, so grains cut from above don't fall on carving below.

The flat end of the pastry knife shears the top into a cone-shape roof. With four shallow stabs and a bit of gentle scraping, the first window appears. Then a door, a balcony, stairs, columns, bricks and stones.

"I like to put a lot of detail in when I carve," she says.

"People ask me, 'Where do your ideas come from?' I don't know how to answer that because I don't know where ideas come from. I do know that when I'm in the shower, I get a lot of good ones. Hot water ... relaxing ... and all of a sudden, bang, I know what I'm going to do in the next contest."

Competitions and workshops on teaching sand sculpture have carried her worldwide, including to South Africa, Asia and Europe. Last summer in a contest in Italy, she took first place in the people's choice category. At a match in Spain, she ranked first in people's choice and third in the juried competition.

Her contest designs take shape in her head or in the sandbox in her backyard. Castles are only one possibility. Characters and architecture also may emerge.

"I can work on a project there for weeks at a time," Sandy says, whereas beach art washes away with the tide.

She's philosophical about her ephemeral art and about the occasional person who can't resist kicking over a castle she's left on a beach.

"It's like buying a rose. You don't expect it to last."

The first tower has been joined by a second and connected by a viaduct with arches. The structure isn't child's play.

"Most people think that sand-castle building is for kids," Sandy says, "and a lot of people who take lessons from me feel sheepish about booking one unless they have some kids along, but I've discovered that most children, especially those under the age of 12 or 13, have about 20 minutes where you really get their attention ... and then they want to go to something else."

It takes an adult or older child to grasp the techniques, she says. When they do, "The light bulb pops on and suddenly, 'Oh, my God, I've got something I can do on the beach all day and not get bored.'"

Plus, "It's therapeutic to have ...