“A whole new world is opening up. A world beneath the sea.”
Those are the opening words of the United States Navy film, “World of the Sea.”
The 1973 documentary that takes the viewer beneath the waves as the narrator explains how the Navy must perform essential support maneuvers underwater, whether it be in submarines or by using divers for missions such as salvage and repair, underwater construction, study of acoustics, or scientific research.
Amidst scenes of divers in the ocean as well as in specialized tanks, the narrator explains
at mark 02:50 how divers need pressurized air to breath in deeper depths, and
at mark 03:25 we see an animated explanation of how a body is decompressed.
The Navy trains divers in a specially constructed ocean simulations facility, shown starting
(Capt. George Foote Bond USN was an American physician who was known as a leader in the field of undersea and hyperbaric medicine and the "Father of Saturation Diving)
The research device is capable of simulating ocean depths of more than 2,000 feet, and
at mark 06:15 we watch as a diver is exposed to pressure equal to 1,025 feet and later 1,200 feet. Following the discussion of medical issues in dives, the film switches to engineering concerns starting at mark 07:25, as we watch scenes of naval engineers test the Mark X breathing device, and divers became “swimming laboratories.”
Deep Diving Systems are discussed starting
at mark 10:55, with scenes of the Mark I and Mark II deep dive systems, which were put into use in the mid-1960s, as well as a personnel diving capsule.
At mark 17:05 a navy captain praises advancements made in deep dive systems, and pledges to continue to dive deeper “and seek the limits of human endurance.”
Meanwhile, the navy is working to enhance underwater communication, the narrator explains
at mark 18:45.
Because divers in submersibles are breathing a helium-oxygen gas mixture, their voices can come across as garbled.
At mark 19:11, sailors are shown working on “unscramblers” to solve the problem.
The film continues as we watch divers continue to work underground and study potential environment issues.
At mark 22:00, we’re told how some of the pressurization techniques used by the Navy also have had practical uses in the civilian medical community.
This Deep Diving System shown in the film was built in 1968 to provide a surface habitat for saturation divers returning from great depths.
Divers are sealed in the habitat and become compressed to the same depth at which they will be working.
After their bodies have become saturated the divers will move from the surface to the working depth and return in the diving bell commonly called a Personnel Transfer Capsule or PTC.
Always maintaining the same pressure, work continues on a 24-hour schedule with divers working and resting alternately for 2 to 3 weeks before decompressing to surface pressure.