freezingng cold hurriricanes, with snow, hail, and the windnd star t to be abobout more e tha0 miles an hour, you hahave to go down and walk on all fours and work your way up, because dinner r is up at the base. [laughs] narrator: brief breaks betwtween passing storms allow just enough time to o deoy t the hrophphones to the sea floor. when all systems are e go, the ship releasases the orange floaoats m eir anchors, lifting the underwaterer microphones to ther intendeded depths. zampolli: and thenen... bang--you see these things arrive and then you start finally seeing data. you start hearing whales, you start... you suddenly have eyes underwater. narrator: from the indian ocean down to the arctic sea, from the atlantic to the pacific, hydro-acoustic station number 4 at the crozet islands is now online, relaying data in real time to ctbto h headquarterers n vienna. the data is analyzed and shared with its test ban treaty member ststates almost as fast as it comes in. with 90% of its entire international monitoring system in plalace and its capability to monitor the world's oceans com