The activities regulations § 94

§ 94 Time limit provisions

The following time limit provisions shall apply when conducting manned subsea operations:
  1. stays at working depth:
    in the case of diving down to 180 metres, the stay at working depth shall not exceed 14 days. With regard to deeper diving, the stay at working depth shall not exceed ten days,
  2. time between saturation periods:
    the time between saturation periods shall at least equal the duration of the previous saturation period. With regard to diving deeper than 180 metres, the time between saturation periods shall be at least twice that of the previous saturation period,
  3. bell run:
    in the case of diving down to 180 metres, the bell run shall not exceed eight hours. With regard to deeper diving, the bell run shall not exceed six hours. If the divers stay dry in a subsea chamber, the bell run can be extended to eight hours. The timing of a bell run begins when the clamp between the bell and the chamber is first loosened and ends when the clamp is reconnected, ready for pressure equalisation and final transfer of the divers back to the chamber complex.
  4. time in water down to 180 metres:
    in the case of diving down to 180 metres, the divers shall not stay in the water for more than four hours during a twelve-hour period. With regard to a three-man bell run, the time in the water can be extended to a total of six hours, provided
    1. the diver returns to the diving bell in the course of the third or fourth working hour in water for least a 30-minute break with the diving helmet off. Breaks in the bell shall be logged, but calculated as part of the total permitted water time of 6 hours, and
    2. the diver has a ”dry day” as a back-up diver in the bell at least every three days,
  5. time in water deeper than 180 metres:
    in the case of diving deeper than 180 metres, the divers shall not stay in the water for more than three hours during a twelve-hour period. The diver shall have a ”dry day” as a back-up diver in the bell at least every three days,
  6. use of breathing mask:
    after a maximum of four hours, divers using a breathing mask in the subsea chamber shall have a break in an atmosphere where use of a breathing mask is not necessary,
  7. recompression following subsea operations:
    after a completed saturation period, the divers shall have immediate access to therapeutic recompression for at least 24 hours following completed decompression. In the case of surface-oriented diving, the divers shall have immediate access to therapeutic recompression of at least 12 hours after completed decompression,
  8. work-free period during work under increased pressure:
    divers working in water or who work under increased ambient pressure, shall, over a 24-hour period, have a continuous work-free period of at least 12 hours. Work and rest periods shall be specified in a shift programme and shall be planned at regular hours,
  9. surface personnel in direct communication with divers in the water: the surface personnel in direct communication with divers in the water shall not perform this function for more than four hours consecutively without a break. The total time in this function shall be limited upward to eight hours over a twelve-hour period.
Section last changed: 01 January 2025

Stays at working depth as mentioned in litera a, means the time between completed compression, alternatively first compression if work is to be carried out at several pressure levels, and start of final decompression.
Bell runs as mentioned in litera c, shall be calculated continuously from when the clamp between the bell and the chamber is first loosened and stops when the clamp is reconnected, ready for pressure equalisation and final transfer of the divers back to the chamber complex.
For work in subsea chambers down to 180 metres requiring time in water which does not exceed more than a total of four hours during a twelve-hour period, as described in litera d, a “dry day” as back-up diver in the bell at least each third day as mentioned in litera d, number 2, is not required. If the diver’s time in water exceeds four hours, litera d with subsections applies.
For work in subsea chambers deeper than 180 metres, as described in litera e, and which requires time in water, the diver shall not conduct any work in water or stay in the water longer than the time it takes to move between the bell and the subsea chamber. A “dry day” as back-up diver in the bell at least each third day as mentioned in litera e, is not required. The bell run as described in litera c, may under such circumstances be extended to eight hours.
Surface personnel as mentioned in litera h, means the diving supervisor or possibly a diving supervisor candidate under qualified leadership.
When stipulating breaks as mentioned in litera h, the workload should be used as a basis; however, the breaks should not be shorter than a half hour. For activity reporting, the break in the bell counts as part of “number of manhours in water”.