Ciao Darwin is a variety game show format created and hosted by Paolo Bonolis (Stefano Magnaghi is the co-creator), and produced by the Italian mass media company Mediaset.
The games involve contestants competing in acts of skill, intelligence and general knowledge, with deliberately ridiculous results, trying to mimic the mechanism of natural selection theorized by Charles Darwin.
The tanks are filled with an initial amount of water determined by the relative scores of the competing teams (usually one increment for every 50 points difference).
There have been some other strange variations, such as two people from the same team sitting together in the tank, contestants blindfolded, creatures like toads, snakes and ducks added, and dyed or foamy water being used.
In the Hungarian and Polish versions, the rule about remaining seated is strictly enforced, and this often leads to the fully clothed contestants being totally under the water by the end.
The voice commentary in the official promotional video for the Ciao Darwin franchise states "each week a winner emerges triumphant, and the loser is left all wet", suggesting that they are not offered a dry change of clothes to go home.