Updated

A 7-year-old boy from Arizona will try to become one of the youngest ever to swim from Alcatraz Island to San Francisco's Aquatic Park on Monday.

Braxton Bilbrey, a second-grader from Glendale, Ariz., who has completed several short-scale youth triathlons, will be accompanied on the estimated 1.4-mile swim with his coach and two other strong adult swimmers.

"It kind of seems like a long way, but I'm not totally worried," said Braxton, whose swim also will be monitored by a Coast Guard watercraft. "It's not that far."

His mother, Stacey Bilbrey, said she is confident her son is well-prepared and will be safe with the other swimmers, who have made the crossing numerous times.

She wasn't originally sold on the idea, but accepted it once he proved he was dedicated to his goal, she said.

"For a 7-year-old to be that motivated and stick with a goal that long is amazing," she said. "Any time a 7-year-old has that strong of a desire, as long as it's a good desire, you should support it. He's worked hard for it."

The second-grader got the idea when he saw a magazine story about a 9-year-old boy who made the swim. Johnny Wilson, a fourth grader from Hillsborough, Calif., completed the swim in 53-degree waters last October in under two hours.

When Braxton asked his swim coach, Joe Zemaitis of Scottsdale, if he thought he could do it, Zemaitis said he thought the second-grader could, thinking he meant some time before he turned 9.

"If you were to ask me if a 7-year-old is old enough to do it, I'd say maybe one out of 10 million," Zemaitis said. "But he's that one."

Braxton has been training two hours a day four times a week. He also did training swims in several Arizona lakes and a trip to the San Francisco Bay last month.