A marine assault course may have been tough for Sportsround's Gavin, but his latest challenge was even tougher - learning to skydive indoors!
"The first thing I saw at Bodyflight was a massive cylinder-shaped tunnel, and even from outside the noise it made was amazing.
The wind tunnel I was sent to is the biggest one of its kind in the world!
It works by firing super-strength winds straight up, which propel the person inside into mid-air.
Top teams taking part
It was quite scary when I was getting shown around the building. A big international competition is taking place this weekend - and teams from all over the world were practising some of their finest flips and twists. How on earth would I compare with that lot?!
You'll believe Gavin can fly!
I was briefed really well before I started by an instructor called Ged. He explained when you're inside the wind tunnel you cannot hear anything at all because the fans are so loud!
I had to learn some hand signals so Ged could tell me what to do. The most important ones seemed to be 'relax' and 'arch your back'.
And it was really important to understand what I needed to do with your arms and legs once I got started.
The wind was really strong
When I walked up to the edge of the tunnel, I could immediately feel the strength of the wind! And I stepped inside, oh my word.
It was one of the most thrilling feelings! The speed of the wind caught me on my belly, and then I was floating in the chamber!
The hardest thing was staying stable.
The winds were so strong, I was battling to keep myself balanced! My face was being pulled in every direction. And my mouth completely dried up! Everything the instructor told me went out of the window at this point!
My chest and arms are still sore now."