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).
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.
