This experiment shows a hand covers of Lycopodium gloves which dive under the water in a transparent tray. The hand of the guy will go out entirely dry. The explanation is easy, the Lycopodium is hydrophobic, this powder on the surface of the water rejects the water when the hand pushes on the powder.
The Lycopodium powder is composed of spores of lycopodium (plant). This plant is used as flash powder for the pyrotechnic effect.

The experiment was carried out by German podcasters Methodisch Inkorrekt.