Chris Calhoun made an excellent video of the training:
Here's two more videos:
First one going into the pool:
When a helicopter crashes in water, the crew has to be able to get out of the aircraft and get their passengers out of the aircraft. "Dunker" training teaches downed aircraft drownproofing to pilots, crew chiefs, flight medics and other aircrew members. On December Drill Weekend, Det. 1 of Charlie Company, 2-104th (Medevac) put eight aircrew members through a day of "Dunker" training. This first video shows a pilot and a flight medic flipping into the deep end of the pool at Somerset Senior High School. They are wearing flight suits and helmets and land upside down in a five-point harness in 12 feet of water. They cannot unstrap until the divers doing the training stop shaking the Dunker--this is to simulate moving blades in the water. Each trainee flipped into the water several times.
Above CW2 Sara Christensen and SSG Pamela Leggore were the lucky duo upside down in the water.
Below is an underwater view of Dunker training.