Several contestants play this game at once. A question is asked and the contestants have to dive underwater to find a card or mat with the right answer on.
In the first version, groups of eight contestants play the game in a hot tub. The answers are all written on cards at the bottom of the tub. The first contestant to find the card with the correct answer to the question on wins, and moves onto the next game.
In the second version, ten contestants at a time play in a swimming pool. At the bottom of the pool are lots of mats with numbers on. A maths equation is read out, and the contestants all have to dive in the pool to and try and find the mat with the correct answer on. The contestant that grabs the right mat and brings it up to the surface wins, and moves onto the next game.
To make diving harder, the contestants all have to wear floats around their waists.
There is more than one question for each group, so the contestants get several chances at winning the game. However, the contestants that don't get to an answer first, after all the questions have been asked, lose the game.