NEDU describes its mission as: "The Navy Experimental Diving Unit tests and evaluates diving, hyperbaric, and other life-support systems and procedures, and conducts research and development in biomedical and environmental physiology. NEDU provides technical recommendations based upon knowledge and experience, to Commander, Naval Sea Systems Command to support operational requirements of our armed forces."
The vision for NEDU is stated to be: "The Navy Experimental Diving Unit will be the most credible and respected research, development, and test and evaluation center for diving as well as the focal point of leadership for biomedical and bioengineering solutions for undersea military operations."
Brooklyn Navy Yard
Experimental diving in the US Navy started in 1912 at the Brooklyn Navy Yard under the leadership of Chief Gunner George D. Stillson. Stillson's research program ultimately led to increasing diver capabilities from 60 feet (18 m) to over 300 feet (91 m) of depth based on Haldane's decompression work with the Royal Navy. This resulted in the first publication of the United States Navy Diving Manual and established the need for a facility dedicated to research and development of diving procedures.
In 1915, Stillson's team was sent to salvage the F-4 submarine. On these deep dives, the divers experienced the debilitating effects of nitrogen narcosis leading them to try the addition of helium to their breathing mix. The navy salvage operations then came under the direction of Warrant Gunner C. L. Tibbals who led teams through the salvage of the S-51 in 1925 and S-4 in 1927 further establishing the naval need for equipment, training, and procedures for rescue operations.
NEDU conducts at least one saturation dive per year. These dives were used, amongst other things, to evaluate decompression and recompression procedures, equipment, carbon dioxide absorbents, as well as active and passive thermal protection. Many of these tests included ongoing evaluations of commercially available diving equipment.
In 1998, the Naval Medical Research Center's diving biomedical and development group was transferred to NEDU.
In response to the overseas military needs, NEDU focused on warm water diving from 1999 to 2002. This guidance to the Naval Special Warfare community influences operational needs on an ongoing basis.
NEDU divers were essential to the recovery of artifacts from the wreck of the USS Monitor in 2001 and 2002.
In 2002, certification of the Mark 16 Mod 1 rebreather was completed following improvement of systems including, extension of the working limit to 300 feet (91 m), new decompression tables for both nitrogen-oxygen and helium-oxygen diving including new repetitive diving capabilities for helium-oxygen, test of an Emergency Breathing System with communications, the addition of an integrated buoyancy compensation device, and an improved full face mask.
In 2011, divers completed a 1,000 fsw saturation dive to evaluate the new Navy's Saturation Fly-Away Diving System (SAT FADS). The SAT FADS was designed in 2006 as a portable replacement of two decommissioned Pigeon-class submarine rescue vessels.
Evaluation and testing of new breathing apparatus and application of other technologies for diving is key to their mission.
Ocean simulation facility
NEDU Ocean Simulation Facility
The Ocean Simulation Facility (OSF) simulates ocean conditions to a maximum pressure equivalent of 2,250 feet (690 m) seawater at any salinity level. The chamber complex consists of a 55,000-US-gallon (210,000 L) wet chamber and five interconnected dry living/working chambers totaling 3,300 cubic feet (93 m3) of space. Wet and dry chamber temperatures can be set from 28 to 104 °F (−2 to 40 °C). Equipped with the latest data acquisition capability, the OSF can accommodate a wide range of complex experiments including diver biomedical studies and testing of humans as well as small submersible vehicles and other machines in the wet chamber. Saturation dives can be performed for more than 30 days of continuous exposure in the OSF. For human and equipment testing underwater over extended periods, divers use the dry chambers as comfortable living quarters, from which they can make diving excursions into the wet chamber. The dry chambers are also capable of altitude simulation studies to heights of 150,000 feet (46,000 m).
Experimental test pool
NEDU experimental test pool
The Experimental Test Pool is a 50,000-US-gallon (190,000 L) capacity freshwater tank measuring 15 ft (4.6 m) by 30 ft (9.1 m) by 15 ft (4.6 m) deep, capable of sustaining temperatures from 34 to 105 °F (1 to 41 °C). It is designed and constructed for manned, shallow water testing and for supporting workup dives for the Ocean Simulation Facility. The test pool is supported by a fully instrumented medical and engineering deck, from which the safety of both divers and test equipment can be monitored. The facility can accommodate a wide range of experiments, from biomedical studies of diver thermal and workload conditions to equipment studies of submersible devices. The test pool has a communications suite, full video capability, real-time computerized data acquisition and analysis, and pressure and gas monitoring.
The Environmental Chamber is capable of simulating a broad range of temperatures from 0 to 130 °F (−18 to 54 °C), humidity from 5 to 95%, and wind velocity from 0 to 20 mph (0 to 32 km/h). The chamber is instrumented to conduct physiological studies and to test various types of equipment.
Experimental diving facility
NEDU experimental diving facility
The Experimental Diving Facility (EDF) simulates unmanned pressure conditions to 1,640 feet (500 m) sea water and temperatures can be set from 28 to 110 °F (−2 to 43 °C). As a complement to the Ocean Simulation Facility, the EDF is used to conduct unmanned testing and evaluation of diving and hyperbaric chamber systems and components. All diving practices and procedures are tested to determine their safety, conformance to established standards, and operational suitability and limits.
The cardiopulmonary laboratory consists of machines that perform a myriad of respiratory function tests and aerobic performance measurements that are often recorded before and after pressure and/or thermal exposure.
The 120 person NEDU Team includes highly qualified and experienced military divers with a combined 1,000 man-years of diving experience: Sea-Air-Land (SEAL), Explosive Ordnance Disposal (EOD), Salvage, Saturation, Seabee, Diving Officer, and Diving Medical Officer (DMO), Ph.D. scientists, engineers, various science-degreed professionals and support personnel.
In December 2016, Commander (now Captain) Jay Young took up his appointment as Commanding Officer of NEDU. He succeeded Commander William Schultz, who had served as CO since August 2013.