Huck Finn has nothing on Lars Alford. At the age of five, Lars is already a two-time veteran of the Jug Bay Homemade Raft Regatta, a strictly-for-fun flotilla of creative crafts that will take place Saturday at Patuxent River Park in Prince George's County. Lars has not only helped paddle his family and friends to victory two years in a row, but he also helps make the winning rafts. This year, Lars' crew, a group of friends and neighbors named Alford, Brown and Green, decided to built two rafts.

"The crew has gotten too big," said Dana Green, who masterminded the group's past victories. "Last year we had eight people and we were too far underwater."

At a recent work session at the Green farm in Bristol, Md., Lars helped with the two rafts, hammering a board onto the bottom of a ping pong table that will form the deck of one and fetching inner tubes to tie onto the bottom of another. When Green needed a small-fingered volunteer to push nails through holes he had made in the bottom of a can that will hold the flag on one of the rafts, he looked naturally to Lars.

Under the flag flies a patchwork banner that reads 'Liberty.'

"The kids made that for the Bicentennial race, but they use it every year," explained Marion Green, mother of crew members Laura, Phyliss, Sue and Katie.

"Mom's making us all corncob pipes," said Sue as she wound masking tape around the bottom of the bamboo flagpole. Last year the crew sported corncob-pipes and straw hats and won a prize, a recycled football trophy, for originality. This year, green hopes also to win the prize that goes to the swift. He is pinning his hopes on two design innovations: a pointed bow and a sheet of plastic nailed on the bottom of the raft.

"You know how we used to get a plastic sheet and wet it and slide across the lawn," Green reminded the kids. "Well maybe a plastic sheet on the bottom of the raft will make us glide through the water faster."

The Greens, Browns and Alfords spend more energy and creative effort than money on the rafts. The raw materials are usually scrounged.

"The ping-pong table belonged to somebody's brother-in-law, and the kids got the inner tubes free from Smitty's Gulf Station. There's probably about $75 worth of lumber here if you bought it, but it all came from our woodpile. This piece of plywood we used three years in a row. Between races I use it to keep the horses out of the hay."

"The first year we had no idea it was even going to float," said Sue.

"It didn't, either," added Katie.

"Look at these inner tubes - all imported," said Lars' father, Bill Alford.

"Yeah, we're really going all out this year," said Green.

According to Rich Dolesh, director of Patuxent River Park, most of the entries are casual craft built out of whatever the participants have handy. One group floated down the river in a tobacco basket, while another crew fashioned a raft out of beer kegs.

"Most are Tom Sawyer-type rafts, but a teen group from Holy Rosary Church in Upper Marboro is building a paddle-wheeler with a sail on it. We're mainly concerned about the safety of the crew, and every homemade raft has to pass a safety inspection. Store-bought rafts can enter, too, but they race in a separate class."

The purpose of regatta is more serious than it appears, according to Dolesh. The Patuxent River, of which Jug Bay is a small part, is supposed to be protected as one of Maryland's wild and scenic rivers, but sewage treatment plants and sand and gravel operations threaten the river's future.

"Look at the stalks of wild rice growing in the marsh," said Dolesh, giving visitors a preview of the regatta's two-mile course.

"The wild rice draws waterfowl, which nest here. We even have bald eagles. But the only way people will want to save and protect what we have here is through personal appreciation - having fun on the river."

Because the ecology of the park is very fragile. Dolesh urges spectators to the regatta to bring their own food, and a trash bag so they can take out what they bring in. No throwaway cans and bottles or alcoholic beverages are permitted. Ice water and soft drinks will be available, but there are no concession stands.

Registration for rafts is supposed to be closed, but Dolesh said he will call him on 6276074.