"Sonar Dome -- An external portion of a sonar dome used exclusively in Thresher class submarines was photographed by the bathyscaph Trieste August 24 during the second series of dives in the area where the nuclear powered submarine Thresher sank April 10."
The original view, from whose caption the quoted text is taken, was released on 5 September 1963.
Official U.S. Navy Photograph, from the collections of the Naval Historical Center.
http://www.history.navy.mil/photos/images/h97000/h97563.jpg Photo #: NH 97563 Wreck of USS Thresher (SSN-593) "Sonar Dome -- An external portion of a sonar dome used exclusively in Thresher class submarines was photographed by the bathyscaph Trieste Au