For safety reasons, the dive plan will need to specify that supervisors need to be able to monitor divers' breathing patterns and receive verbal reports from the divers of their condition. There is no requirement to monitor the temperature, heart rate or other physiological parameters of the diver because this information will not assist the supervisors' assessment of safety.

9.9.2        Seismic Operations and Sonar Transmissions

There are inherent problems for divers who are close to seismic operations or sonar transmissions. If there is any possibility of sonar activity or seismic activity in the vicinity of a diving project, the dive plan will need to include parameters for the safety of the diver.

Divers are at risk of decompression illness (DC1) after diving. It is difficult to treat decompression illness if recompression facilities are not immediately available. The dive plan will therefore need to specify that divers remain close to suitable recompression facilities for a set time following a dive.

9.9.4        Flying after diving

The dive plan will need to state that flying is avoided for a specified time following a dive because of the decrease in pressure on the diverts body caused by increased altitude and the resultant increased risk for decompression sickness.

If transportation is required (e.g. for medical evacuation), the altitude and in-flight conditions shall be recommended by the level 2 Designated Medical Practitioner. The cabin pressure of the aircraft shall not be less than the equivalent of an altitude of 300m (approximately 1000ft) above the dive site.

9.9.5        Thermal stress

The dive plan will need to specify ways in which divers can be maintained in thermal balance because excessive heat or cold can affect their health, safety and efficiency. For example, divers may be provided with suitable passive or active heating, such as thermal undergarments and a well-fitting "dry" diving suit, or a hot -water suit. Conversely in very warm waters nothing more than cotton overalls may be required.