No worries on drowning on this one, there was a guy on the other side watching everything underwater, ready to take action if a model got into difficulty. And all the photographers were stood nice and dry outside looking through the 'window'

Fair play to the models on this one... strike an interesting pose, without limbs or fabric or even bubbles spoiling the shot, and only having 20-30 seconds to do it before they have to come up for air, I'm not sure I could do it haha