What doesn't say the video if that, just after I stopped to record, the Shark flew away (given that the infrared remote control range is about 10m only), and disappeared very high in the sky. We didn't have the time to catch it, and possibly, the sun warmed the helium inside the envelop and made the shark to climb quickly... too bad !
So don't be surprised if, somewhere in the french alps, even at 3000m of altitude, you meet a shark :) !!!