CHAPTER 8 — Surface Supplied Air Diving Operations
8-1
C H A P T E R 8
Surface Supplied Air
Diving Operations
8-1
INTRODUCTION
8-1.1
Purpose. Surface supplied air diving includes those forms of diving where air is
supplied from the surface to the diver by a flexible hose. The Navy Surface
Supplied Diving Systems (SSDS) are used primarily for operations to 190 feet of
seawater (fsw).
8-1.2
Scope. This chapter identifies the required equipment and procedures for using
the UBA MK 21 MOD 1 and the UBA MK 20 MOD 0 surface supplied diving
equipment.
8-2
MK 21 MOD 1
The MK 21 MOD 1 is an open cir-
cuit, demand, diving helmet (Figure
8-1). The maximum working depth
for air diving operations using the
MK 21 MOD 1 system is 190 fsw.
The MK 21 MOD 1 system may be
used up to 60 fsw without an Emer-
gency Gas Supply (EGS). An EGS is
mandatory at depths deeper than 60
fsw and when diving inside a wreck
or enclosed space. The Diving Super-
visor may elect to use an EGS that
can be man-carried or located outside
the wreck or enclosed space and con-
nected to the diver with a 50 to 150
foot whip. Planned air dives below
190 fsw require CNO approval.
8-2.1
Operation and Maintenance. The technical manual for the MK 21 MOD 1 is
NAVSEA S6560-AG-OMP-010, Technical Manual, Operation and Maintenance
Instructions, Underwater Breathing Apparatus MK 21 MOD 1 Surface Supported
Diving System. To ensure safe and reliable service, the MK 21 MOD 1 system
must be maintained and repaired in accordance with PMS procedures and the MK
21 MOD 1 operation and maintenance manual.
8-2.2
Air Supply. Air for the MK 21 MOD 1 system is supplied from the surface by
either an air compressor or a bank of high pressure air flasks as described in para-
graph 8-7.2.3.
Figure 8-1. MK 21 MOD 1 SSDS.
