I am taking in the view from high above the lake when Callum’s voice comes over the earpiece in my helmet. He wants me to try a dive. So I spread my arms wide, lean forward and fall from the sky. In the next second or so I plunge into the calm green lake and all goes quiet, save for the deep rumble coming from my feet.

This is not over yet though. Arms stretched out before me, I shoot across the lake bottom, then remember to arch my back, look upwards, and promptly rocket out the water and back into the air. I blink to get my bearings, and open my arms again, just in time for the next dive.

An hour earlier, I would have ruled out dolphin dives on my first encounter with a flyboard. Safe to say, I was not a natural. There is a knack to flying around in a pair of boots that keep you aloft by blasting 1,000 gallons of water a minute directly downwards. But what is most surprising about this ludicrous and exhilarating water sport is that it isn’t that hard to grasp the basics.

Before my first go, Callum, an instructor at Action Watersports in Lydd, Kent, explained how it worked. The flyboard is hooked up to a jetski by a bendy tube about 18m long. Open the jetski’s throttle, and the engine thrusts water at high speed down the tube and into the flyboard, where it shoots out of two nozzles in the bottom. The jetski driver controls the power, thus how high you fly. All you have to do is stay on the thing.

Under Callum’s instruction, I donned a helmet, strapped my feet into the boots on top of the flyboard and leapt into the lake. I lay on my front, straight as an arrow, and pulled my head up. Callum fired up the jetski and with a rumble of water, pushed me out into the lake, telling me to lean left or right to reach the spot for my first attempt at take-off.

To get airborne, I lay on my front with my arms close to my side, and gently bent my legs until the flyboard came underneath me. When I was upright in the water, I pushed my legs straight, locked my knees and ankles and stood bolt upright. If you’re lucky and have a good sense of balance, you’ll rise into the air with grace and poise. When you are clear of the water, let your knees bend a little, relax your shoulders and look at the horizon to steady yourself. To steer left, bend and turn the right knee in a little and vice-versa.

I did not rise with grace or poise. I was too tense, too rigid. But after a few goes, it came together. I rose and hovered over the water. One metre up, five metres up, 10 metres up. I moved left and right, albeit gingerly. The voice in my head boomed: I’m Ironman! But as I scanned the horizon for people to save, or failing that, my nemesis, I fell again – this time backwards, in a heavy heap into the water.

While I had a rest, Callum and Molly, another instructor, showed me how it should be done. Molly swooped and dived like a swallow, Callum pulled off spins and backflips. They could fly the board alone, thanks to a wireless handheld throttle that gives the rider direct control of the jetski’s engine.

If you love going fast on the water, a flyboard might not trump the buzz of waterskiing or wakeboarding, and at £95 a session, it costs more. But for sheer ridiculous fun, there is nothing quite like a flyboard. Just beware of low-flying aircraft.