Gavin Phillips is ahead of the game when it comes to realizing childhood ambitions.

“When I was a kid, I told my mom, ‘One day, I want to be one of those divers,’” the now 20-year-old says of visiting the National Aquarium in Baltimore at age 5.

When an exhibit-guide position opened, Phillips, then 14, jumped at the chance. Later promoted to aquarist assistant at age 16, he started collecting hands-on experience with the animals. But to get in the tank two years later, “Scuba G” — as his friends now call him — Phillips had to pass two tests: one written and one in-water, which included a logic puzzle, gear removal and fitting through small spaces.

Passing led to his current gig as a volunteer scuba diver responsible for feeding tarpon, hogfish, cownose rays, and — his favorite — a 500-pound green sea turtle named Calypso.

“It’s a cool way to keep up with my dive skills and help out,” says the ­environmental science major at the University of Delaware. “We’re ­raising awareness. People don’t know that these ­animals are endangered until they learn at the aquarium.”

The best part? “I love interacting with the kids,” he says. “I hope I inspire them to pursue their passions.”

WHY HE DIVES

Age When Certified: 16

Level of Certification: PADI Rescue Diver

Hometown/School: Forest Hill, Maryland/University of Delaware

Favorite Dive Destination: Bonaire

Most Memorable Dive: On a night dive in Bonaire, a tarpon came flying at my light. It was hunting the fish swimming in the beam!

Funniest Thing That Happened to Me Underwater: At the aquarium, I always have little kids waving, trying to take pictures with me. We play around with that.

Who I most want to dive with: Capt. Don — the father of Bonaire diving.