(a) Each breathing supply hose must—

1. (1) Have a maximum working pressure that is equal to or exceeds—

   1. (i) The maximum working pressure of the section of the breathing supply system in which used; and
   2. (ii) The pressure equivalent of the maximum depth of the dive relative to the supply source plus 100 psig;
2. (2) Have a bursting pressure of four times its maximum working pressure;

3. (3) Have connectors that—

   1. (i) Are made of corrosion-resistant material;
   2. (ii) Are resistant to accidental disengagement; and
   3. (iii) Have a maximum working pressure that is at least equal to the maximum working pressure of the hose to which they are attached; and

4. (4) Resist kinking by—

   1. (i) Being made of kink-resistant materials; or
   2. (ii) Having exterior support.

(b) Each umbilical must—

1. (1) Meet the requirements of paragraph (a) of this section; and
2. (2) Be marked from the diver or open bell end in 10-foot intervals to 100 feet and in 50-foot intervals thereafter.