Australian Diving Regulations

All occupational compressed air diving in the Commonwealth of Australia must comply with the Australian Standard AS2299 "Occupational Diving".

The standard outlines the number of personnel to be used, the type of equipment and its maintenance, decompression
procedures, and the paperwork to be kept.
The standard requires that the Diving Team be composed of four people whose roles are as follow:

The Supervisor - whose duty is to ensure that all diving is carried out in compliance with the standard

The Diver - who enters the water and perform as the task.

The Stand By Diver - who shall be ready to assist the diver is necessary

The Attendant - who is a general hand to assist the diver and handle the hoses.
In practise, the dive team usually is composed of three persons, with the Supervisor acting as
the Attendant, when the water depth is less than 20 metres deep. 
There are three types of Compressed Air Diving covered by AS2299:

1. SCUBA (Self Contained Underwater Breathing Apparatus
2. SSBA - Surface Supplied Breathing Apparatus
3.SRD Surface Recompression Diving

SCUBA is diving with your air supply on your back. Use is limited under AS2299 to
operations not involving cranes, power tools, limited surface access, prolonged exertion or
depths in excess of 30 metres. The reason for this is the limited air supply. SCUBA is
ideally suited to inspection dives, scientific research on marine life, underwater photography.

SSBA is the usual choice for Commercial Diving because the Diver has an unlimited air
supply from the surface compressor and or bottled air via his air hose.

SRD involves the Diver carrying out his decompression in a Recompression Chamber on the Surface. SRD allows the surface team greater control over the decompression of the diver because of the controlled environment the chamber creates.

Diver Training and Certification

In Australia the Commonwealth Government controls the regulation of Commercial Diving through the Australian Diver Accreditation scheme (ADAS). 
All divers working as an occupation other than self employed abalone divers must have an ADAS certification. There are four ADAS certification levels:

Level One - SCUBA Diving without tools
Level Two - Surface Supplied Diving 
Level Three - Surface Recompression Diving on Air
Level Four - Mixed Gas Diving

The training requirements for ADAS certification are laid down in Australian Standard 2815 parts 1 to 4. In order to meet the training criteria the would-be diver must attend an accredited Diver Training school.