Restricted surface visibility caused by, for example, by fog or driving rain may affect the safety of the operation. The dive plan should identify when operations will need to be suspended because of restricted visibility .

The dive plan should consider the presence of currents and the limitations they impose on the diver's operational ability. While other parameters must also be taken into account, tide meters may provide accurate information on the tidal current at different depths and can be used to assess the diving conditions.

Diving operations can be complicated by the number of lines deployed during operations: equipment guide lines, clump weights and wires and diver's and bell umbilicals, swim lines etc. This situation is however often simplified by the level of detailed planning involved in the operation, resulting in all involved parties having a clear understanding of responsibilities and expectations.

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.

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:

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

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

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:

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

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 marine life. If so, suitable emergency and contingency plans should be put in place.

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.

Divers are required to operate from different locations with varying levels of support. Due consideration must be given to the effect each location will have on the safety and efficiency of an operation.

Prior to mobilisation it is recommended that a suitable person (this may be the diving supervisor) should inspect the site and decide on the optimum location for the system.  The level of services should also be assessed.

While it is not necessary for the various components of the diving system to be placed in a single location, care should be taken when considering hose or cable runs which exceed standard system lengths. Hose and cable runs should be protected from physical damage and should not cause a hazard to personnel.

Due account should be taken of voltage and/or pressure drops due to length, and communications between different locations considered.

Diving activities shall not be carried out from a diving station located more than 3m above the water unless the divers are transported through the air-water interface by a suitable stage, ladder, or wet bell.

Whichever method is chosen, provision must be made for the recovery and transport of an unconscious diver.

Before a diver approaches a worksite that may be made hazardous due to operation of mechanisms, specific care must be taken to ensure that such mechanisms are secured against inadvertent movement before the diver enters the water and kept secured by means of proper lockout procedures.

Where explosives are handled in diving operations, the employer shall refer to the recommendations and regulations of the appropriate authority for their transportation, storage, and use.

Deep diving applies to diving operations for depths greater than 50 metres and includes bell, saturation, bounce (non-saturation), and submersible lockout diving as well as sea bottom habitat dives.  This information is covered in the offshore code.

Where surface mixed gas and saturation diving techniques are used, the employer and the diving supervisor shall refer to the Offshore Code of Practice.

When diving in contaminated waters (biological, chemical, physical.), the employer will ensure that all the relevant Regulations are complied with, as well as any specific local authority regulations that may be applicable.

It is the duty of the employer to identify all confined spaces present at a diving project and ensure that the requirements of confined space entry stipulated in the General Safety Regulations are complied with.

The employer must also take cognizance of risks associated with differential pressure situations as well as the risks associated with possible entrapment and manage these risks appropriately.