The way the work is done is mind blowing[0]. The divers have to go so deep they need to live in helium tanks for more than a month, to make sure that their blo

The way the work is done is mind blowing[0]. The divers have to go so deep they need to live in helium tanks for more than a month, to make sure that their blood is sufficiently saturated with the gas. The helium is the only way they can dive deep enough, and yes, it does make their voices high pitched the entire time they are in there. [0] http://www.nytimes.com/2008/11/23/nyregion/23tunnel.html?pagewanted=all http://www.nytimes.com/2008/11/23/nyregion/23tunnel.html?pag...