Pro Skaters -- INSANE VIDEO ... Shredding Empty Waterpark

It's every skater's dream ... having carte blanche to grab your board and RIP down empty waterslides at an empty waterpark ... without security trying to chase you out the door.

And that's exactly what happened at the Aquaventure Waterpark at Atlantis, The Palm in Dubai when 3 pro skaters -- Milton Martinez, Alex Sorgente and Jan Hoffmann -- hooked up with Red Bull UAE and got the ultimate all-access pass.

You gotta watch this video ... these guys are hitting tricks on open-air tubes HIGH above the ground -- meaning one false move and SPLAT.