Call it vacation Bible school with a twist:

Little "T.C." threw his four-foot frame between a makeshift castle and the tide, hugging the small clump of sand as if it were his best friend about to move away.

As the Atlantic Ocean swept over the castle, 19-year-old Tom Campbell said: "You just learned a good lesson. You can't hold back the tide."

Life lessons. Moral lessons. Bible lessons. And a tan.

T.C. (for Too Cool), whose real name is Andrew Huckabee, is a third-grader at Bethlehem Baptist Christian Academy in Fairfax. But for the past week, he was among three dozen children gathered at Rehoboth Beach, Del., for free religious instruction and fun.

The program, Children's Sand and Surf Mission, is part of Scripture Union, an international nonprofit Christian youth education organization. The organization dates to 1867 when founder Josiah Spiers, a 24-year-old clerk from London, befriended and taught scripture to a group of children while vacationing on a beach in Llandudno, Wales.

The motto of the program, which now has children's missions in 140 countries, is quite explicit: "Children and young people and their families will know God's love, follow Jesus and meet God daily in His word."

Each summer in the United States, more than 3,000 children ages 4 to 14 receive that word on East Coast beaches from Cape Cod, Mass., to Daytona, Fla., in free 90-minute morning sessions that include a play, puppet show, Bible verse memorization, Bible quiz and games. Each evening, the children gather for an hour for the "Bible Diggers," a short Bible study, then share games and fellowship, while their parents enjoy a free hour to explore the boardwalk. On the last night of each week, the volunteers throw a party with cake and juice for their young charges at which each child is given a Bible with each volunteer's signature, address and telephone number.

The organization includes more than 600 teen and adult volunteers, many of whom attended the beach Bible sessions as children. The volunteers use beach names such as Runner and Sweeper rather than Mr. and Ms. as part of the effort to make the Bible seem fun.

The mission also runs Children's Street and Sidewalk Mission programs in parks in New York City, Miami, Seattle/Tacoma and Milwaukee. Recently, the organization began a children's ministry built around soccer in Milwaukee and Seattle/Tacoma. The mission programs are financed by donations received by Scripture Union, said Dan Sheldon, Scripture Union's director of finance and administration.

"We like to say we share a good time and the good news," said Jack Nelson, vice president of the mission program. "In the context of the beach or a city park, we are going where children are to some kids who may not normally attend church and giving them an enjoyable context in which to understand God's truth."

Bible sessions are held in "stadiums" built daily by the teen counselors and adult volunteers who construct seven-foot terraced stands in the sand, along with a six-foot sand podium.

"We use the environment we are in to illustrate and obviously provide a conducive setting to talking about God's creation and His power, which nature does," Nelson said. "If we're talking about creation and God's power, we have kids look at the ocean, and they can see His vastness and His power."

On Wednesday, the 14 volunteers gathered at Rehoboth spent two hours packing sand and carrying and dumping 750 gallons of water to build the stadium, before cleaning up and donning costumes to perform "The Blind Man Sees," to illustrate that day's theme: Jesus is the Light of the World, which the children memorized from John 8:12.

"Who is Jesus?" counselor Monica Huckabee, 14, a k a Spice, asked the children during the Bible quiz. "Who loves Jesus?"

A chorus of three dozen tiny voices keened: "I do! I do! I do!"

Andrew Franke, 35, a Christian publishing salesman from Alexandria, known on the beach as Nimble, has led the Rehoboth Beach program for three years with his wife, Mindy, a k a Thimble (spouses' names must rhyme).

"A lot of families plan their vacations around us," Franke said. "The children learn about Jesus and the Bible and have a good time. The parents love it because they get a break."

Debbie King, of Morgantown, W.Va., said her family has planned its summer vacations at Rehoboth to coincide with Children's Sand and Surf Mission for nine years to allow her daughter Ashley, 12, who wants to be a counselor, and son, Jeffrey, 8, to get a dose of religion by the sea.

"It has been a spiritual blessing through and through for our entire family," King said.

The program also fosters closeness among the volunteers. Each team of teen and adult volunteers is housed together for the one-week or two-week programs, sharing chores and family-style meals. The volunteers hike the mile plus to the stadium area in front of the Henlopen Hotel and back. Each afternoon, the teenagers and adults meet for a devotional and team meeting. Thursday night, they go out for "grazing," in which they surf the Rehoboth Boardwalk for desserts and junk food. Friday is pizza night.

As he ate lunch one day last week, T.C. Huckabee pondered his week on the beach. Despite the loss of his castle, he enjoyed himself and wants to return.

"We learn good stuff," he said. "But mostly we have a lot of fun."