he Submarine Escape Training Tower (SETT) at HMS Dolphin in Gosport, UK. Built in the 1950's and still one of the premier training facilities for sub-mariners in the world... but far better put to use as a Freediver's playground!

The SETT is an awesome sight. Standing 10 stories tall and visible on the horizon for miles around it is only when you are standing in the car-park at it's base, looking up those walls that it suddenly dawns on you just how deep -30m really is. But if you thought that was bad enough your first look into the water will be quite an experience... standing at the top of the tank looking over the edge you can actually see the bottom of the pool as clear as day. Vertigo sufferers need not apply!