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Occupational Health and Safety Act, 1993 (Act No. 85 of 1993)

Code of Practice

Diving Regulations, 2009

Code of Practice for Inshore Diving

10. Special operational conditions

10.7 Risks from the environment

 

The safe and efficient deployment and operation of divers is dependent upon suitable environmental conditions. For any given situation the combination of these conditions can be dramatically different and it is the responsibility of the diving supervisor to assess all available information before deciding to conduct, to continue or to finish diving operations. The operations manual must contain clear limits for hazards from the environment.

 

At no time should a diving supervisor allow contractual pressure to compromise the safety of personnel during ongoing or planned diving operations.

 

The following sub-sections are designed to highlight environmental aspects that affect diving operations. There is not, however, any substitute for practical experience.

 

10.7.1        Water depth and characteristics

 

Water characteristics may have a significant effect and the following factors should be taken into account when assessing the use of a diver on a given task:

Visibility - Poor visibility can alter the effectiveness of the operation. Diving operations near or on the bottom can stir up fine grained sediment which may reduce visibility, particularly in low or zero current situations.
Temperature - Extreme temperatures (both high and low) may affect the reliability of equipment and impose particular hazards on personnel.
Pollutants - The presence of man-made and natural petroleum products around oil fields can cloud optical lenses and may damage plastic materials. Equally gas can affect visibility, block sound transmission and cause sudden loss of buoyancy. Special precautions should be taken to protect the divers if pollutants are present as well as protecting personnel who may handle the divers or their equipment during launch / recovery and during maintenance.
Shallow water - Divers are very sensitive to water movement and great care has to be taken in shallow water where surge of the water can have a major effect on the ability of a diver to remain in a particular position.

10.7.2        Currents

 

Currents can cause considerable problems in diving operations but unfortunately it is often the case that very little quantitative data on particular current profiles is available.

 

Simulations and analysis can provide good indications of the effect of currents but often currents are not constant even close to the seabed. Currents vary with location and surface currents can be quickly affected by wind direction.

 

The use of a tide/current meter may provide information on the current strength and direction at any particular depth.

 

10.7.3 Sea state

 

The sea state can affect every stage of a diving operation.

 

Working from a boat or vessel in rough seas requires careful consideration.

 

Rough seas also require a heightened awareness of the possibility of accidents.

 

Rough seas increase the risk to the divers, and may make rescue operations impossible or unacceptably dangerous

 

10.7.4        Weather

 

The cost and efficiency of operations can be adversely altered by the effects of weather. While divers under water may not be directly affected by the various effects of weather, these can have an effect on diving operations in a number of different ways:

Wind speed and direction can make the diving operation difficult.
Rain and fog will cause a reduction in surface visibility, possibly creating a hazard at the surface.
Bad weather can affect surface workings, particularly with adverse combinations of wind, rain,etc.;
Hot weather can cause overheating. In particular umbilicals stored on deck are more susceptibe to overheating by warm air or direct sunlight.
Extreme heat, including direct sunlight (or cold) can cause the temperature inside deck chambers to rise (or fall) to dangerous levels. In such conditions the internal temperature should be monitored and kept at a comfortable level.
Extreme heat (including direct sunlight) or cold can adversely affect the diver acting as standby who will be static but dressed in most of his diving equipment. Arrangements should be made to keep the standby diver sheltered, at a comfortable temperature and well hydrated.
Electric storms or lightning may be a hazard to exposed personnel or equipment.

 

Operations should, therefore, be carefully monitored with regard to the safe of both personnel and equipment.

 

10.7.5        Hazardous marine life

 

In some parts of the country divers may come in contact with marine life which will pose a hazard. Prior to commencing diving operations it should therefore be established if there is any known local hazard of this type.

 

If hazardous marine life is suspected then suitable emergency and contingency plans should be drawn up in consultation with the level 2 Designated Medical Practitioner to deal with its effects.

 

10.7.6        Other considerations

 

A diving supervisor should only allow a diving operation to begin after he has carefully considered all relevant environmental criteria, their interaction with each other, and other factors including the deployment equipment, the system's readiness, crew readiness and the nature and urgency of the tasks.

 

This will normally form part of the Risk Assessment carried out for that operation.