In 1942, French explorer Jacques-Yves Cousteau, together with engineer E. Gagnan, invented scuba gear. About his work before this invention and about the studies performed with scuba, J.-I. Cousteau and F. Dagen narrate in "In the World of Silence." New designs implemented under the leadership of J.-I. Cousteau, - "diving dishes," underwater houses - the next stage in human exploration of hydrocosmos. These works and voyages of the expedition vessel "Calypso" are mentioned in the book "Living Sea."