# OCEANOGRAPHIC RESEARCH OF DEEP SCATTERING LAYER BY SONAR AND HYDROPHONE 21944

Made in the 1970s this film THE DEEP SCATTERING LAYER tells the story of the search for a mysterious "second floor" in the ocean, as recorded by sonar devices. This floor -- consisting of marine animals such as shrimp, whales and dolphins -- moves to different levels at different hours, different days, and different seasons. It is probed by U.S. Navy sonar, deep-trawled nets with hydrophones and instruments, and finally by by ocean going submersibles. While the film presents the research primarily in scientific terms, the study of these sound return layers was also viewed as extremely important by the Navy for tactical reasons to do with submarine operations. Includes footage of ocean life, sonar / echometer (or " the echo sounder ") and hydrophones, deep sea and SCUBA diving, and submarine operations. A portion of the film was shot at the Woods Hole Oceanographic Institution. Some of the rare footage shown includes . including the use of small submarines shown at 2:44 , the Star III submersible ( 13:08 ) and the bathyscaphe Trieste ( 12:59 ). At 18:10 , the Navy's Underwater Sound Research Laboratory at the Undersea Research and Development Center San Diego is shown at 18:20 . At 25:40 , project Ocean Acre is seen, with a research team led by Dr. Charles Brown of the Sound Lab studying a patch of sea water near Bermuda. The study looked at the acoustic signature vs. the biological content of the scattering layer over the seasons and eventually determined that sound…

- Kind: Film
- Genres: Industrial and advertising
- Archive: [Internet Archive](https://archive.org/details/21944OceanPhenomenonTheDeepScatteringLayer)
- Licence or status: none stated by the archive
- Who can watch: Tweens profiles and older (the archive gives no rating; placed by Invisible Network from its collection and subjects)

[Watch now](https://invisiblenetwork.ai/watch/archive/ia/21944OceanPhenomenonTheDeepScatteringLayer?play=1)