mario zampolli: those places, the roaring forties, are legendary among sailors and people who work at sea as some as some of the most difficult oceans in the world. you have what is called an unlimited fetch, currents that are also merging, coming down from south africa, merging with certain polar currents, that go all around the world, really undisturbed. in these difficult conditions was really something that p put a lot of streress on everybody, on all the tteams. you know that you'u're t afafforded, you'u're not allllod many mistakes. patrick grenard: of course it's not only a harsh environment above the sea surface, it's also a harsh environment underwater. but we knew that we had a mission to accomplish. it was to install that station despite the difficiculties, despe e the harsh environment, the complexity of the project, we had toto do it. man: once we get going, we can adjust it, ok? narrator: after more than 4 years of meticulous planning, two triplets of underwater microphones called hydrophones are finally loaded onto a specialized cable ship. ststanley: we have to be very