There are several modes of diving that are characterized by the diving equipment
used. The following descriptions outline capabilities and logistical requirements
for various mixed-gas diving systems.
Minimum Required Equipment. Minimum required equipment for the pool phase
of dive training conducted at Navy diving schools may be modified as necessary.
Any modifications to the minimum required equipment listed herein must be
noted in approved lesson training guides.
Minimum Equipment:
1. MK 21 MOD 1 helmet with tethered umbilical
2. Thermal protection garment
3. Weight belt
4. Dive knife
5. Swim fins or shoes/booties
6. EGS bottle with submersible tank pressure gauge
7. Integrated diver’s vest/harness
MK 21 MOD 1 Lightweight Surface-Supplied Helium-Oxygen Description.
Principle of Operation:.
Surface-supplied open-circuit mixedgas (HeO2)
system.
Operational Considerations:
1. Adequate mixed-gas supply
2. Master Diver required on station for mixed-gas operations
3. Diving Medical Officer required on-site for dives deeper than
300 fsw
4. Recompression chamber required on-site
5. Planned exceptional exposure dives or dives exceeding normal
working limits require CNO approval
6. Breathing gas heater
7. Hot water suit
13-8.3 Flyaway Dive System III Mixed Gas System (FMGS). The FADS III Mixed Gas
System (FMGS) is a portable, self-contained, surface-supplied diver life-support
system designed to support mixed gas dive missions to 300 fsw (Figure 13-5 and
Figure 13-6). The FMGS consists of five gas rack assemblies, one air supply rack
assembly (ASRA), one oxygen supply rack assembly (OSRA), and three heliumoxygen
supply rack assemblies (HOSRA). Each rack consists of nine 3.15 cu ft
floodable volume composite flasks vertically mounted in rack assembly. The
ASRA will hold 9600 scf of compressed air at 5000 psi. Compressed air is
provided by a 5000 psi air compressor assembly, which includes an air purification
system. Oxygen is stored at 3000 psi. The FMGS also includes a mixed-gas
control console assembly (MGCCA) and two gas booster assemblies for use in
charging the OSRA and HOSRA. Three banks of two, three, and four flasks allow
the ASRA to provide air to the divers as well as air to support chamber operations.
Set-up and operating procedures for the FMGS are found in the Operating and
Maintenance Technical Manual for Fly Away Dive System (FADS) III Mixed Gas
System, S9592-B2-OMI-010.
