BYRON -- With a couple of shrill blasts from a coach's whistle, the handful of youngsters formed a line, took aim and released their bowstrings.

Thwack!

Arrows thudded into the targets at the far end of Excelsior Middle School's gymnasium, marking the start of another practice session for the Discovery Bay students.

"I like archery from all the books (about) medieval times, all the archers and castles," said 13-year-old Rachel Landro, who never had shot an arrow before becoming one of the first members of Byron Union School District's after-school Archery Club two years ago.

Project Straight Arrow is the brainchild of county Deputy Sheriff David Allain, who came up with the idea of offering weekly archery lessons as a way to keep youngsters out of trouble on the days that school finished early and working parents weren't around to keep an eye on them.

As the district's new school resource officer, Allain also reasoned that sharing his love of archery would be a way to get to know some of the kids he'd be mentoring.

What's more, he thought archery could be an option for youth who hadn't excelled on a court or playing field.

"A lot of kids don't quite click with the traditional sports like basketball and football," Allain said. "I think (archery) just fills a niche."

That was the case with Cameron Mossor, 13, who found his groove when he picked up a bow and arrow.

"I suck at all the other sports. I'm better at shooting things," said the eighth-grader, who estimates he now can hit the bull's-eye four out of five times.

And so Allain applied to the California Department of Fish and Wildlife, which promotes archery education in schools and certifies trainers like Allain. The agency came through with approximately $3,000 worth of equipment -- a dozen bows, six dozen arrows, a bow rack and five targets -- and Byron Union became the only school district in the county with an archery instructor certified by the state to teach the sport.

Together with another volunteer, Allain rotates among the district's three campuses, spending three months at each.

Using multihued aluminum and fiberglass bows -- each color represents a different tensile strength up to about 25 pounds -- students spend 2½ hours a week working on their technique as they aim small-tipped arrows at a bull's-eye.

"This is pretty much about fine tuning," Landro said, demonstrating how even a slight shift in her stance or moving the hand that's drawn the string can alter the arrow's trajectory.

And that's why Allain hammers home his safety rules.

Five whistle blows is a signal to stop shooting immediately, an all-important command should someone inadvertently walk in front of the targets or another archer absentmindedly move out of line to collect an arrow that's dropped on the floor instead of raising his hand for a coach to bring a replacement.

There's also a protocol for removing arrows embedded in the targets: Look behind when you're pulling to avoid giving anyone standing behind you an extra "belly button," and hold the set you recover at both ends to avoid jabbing yourself if you trip, Allain tells kids.

Club members only shoot inside the gym and, except for the entrance, the doors all stay locked. In addition, a safety curtain behind the targets prevents arrows from ricocheting off the wall.

The result? Every student not only still has both eyes but there hasn't been a single other injury in three years of classes.

The hand-eye coordination that his students have developed is such that four of them, including Landro and Mossor, are heading to Louisville, Ky., next month for the club's first national tournament after qualifying at a state competition in February.

With a quiver of 30 arrows each, they'll be aiming to rack up 10 points for every perfect shot.

"When these kids started they were hitting the floor, the curtain," said archer Al Harcourt, who coaches with Allain. "Now they're going to the nationals."

Contact Rowena Coetsee at 925-779-7141. Follow her at Twitter.com/RowenaCoetsee.