Derek Vanboeschoten zips ups his jumpsuit and straps on a helmet and goggles.

Teaching a group of nine students, he motions for them to follow him into a large, Plexiglas-covered tunnel, which is noisy with the rush of 120 mile per hour winds. Vanboeschoten shoots a quick glance toward the tunnel's operator and when he gets the OK to start, signals for the first student to dive in.

As a wind tunnel instructor at SkyVenture Colorado in Lone Tree, Vanboeschoten spends his days helping people experience the feeling of skydiving -- without the drop of 1,200 feet from a plane. The 35-year-old Littleton resident has been an instructor for SkyVenture for the past two years. He first got interested in skydiving in June 1994 when he was in the Army.

"A group of us got together and I made my first parachute jump," he said. " I liked it and didn't look back."

He's made about 3,300 skydives in his lifetime. However, Vanboeschoten admits he's not a thrill seeker. And with skydiving, he said there's no feeling of acceleration like in base-jumping, because it feels like you're laying on a cushion of air.

Lessons for each student last about two to three minutes. One minute inside the 45-foot-tall tunnel is enough to simulate the skydiving experience. While inside, students try to maintain a prone position, finding their balance amid rushing winds.

Vanboeschoten is right inside with the students June 5, adjusting their bodies and communicating with them when they have to straighten or bend their legs. He does this through hand signals since it's difficult to hear anyone talk in the enclosed space, he said.

Because of the close quarters, students do bump against the walls and floor. But each student has to wear helmets, goggles, elbow and kneepads to ensure safe flying. As Vanboeschoten directs one young student to adjust her body, she flies into the doorway frame, but he catches her just in time and corrects her.

Vanboeschoten walks around the tunnel as he instructs the class, amazingly keeping his vertical stance, since the students seem to flop helplessly from side to side. He said it takes a week of intensive training for instructors to learn how to walk. But he does it with ease, even kneeling down once in a while and jumping from one wall to another as he leads his students.

Vanboeschoten is one of 16 instructors at SkyVenture, 9230 Park Meadows Drive in Lone Tree, with half of them being full-time. He said he enjoys his job because he's "dealing with very happy people; people who are having a good time."

"It's a positive place to work," he adds, "You have a lot of respect and trust between instructors. We have a high standard here; we try to up the bar as instructors and always try to do better."