The Extended Range Diver Level 4 ERD course is the ultimate certification for divers who wish to dive beyond normal limits without the use of tri-mix gases. This course is also a prerequisite for those divers who wish to progress and become intermediate tri-mix and or full tri-mix divers. The ERD course includes both theory and open water sessions. Within the ERD course the main aim is not greater depth but mission orientated dive planning. Divers will learn to use dive-planning software (ANDI GAP and some other models) to maximize the efficiency of using EAN and oxygen in their dives.

Within the four open water sessions that are part of this course you will make dives using different equipment configurations and gas mixtures. Dives will be made using twin sets and stage tanks with an unlimited configuration of equipment and gases. The maximum depth of dives will be 50m with an unlimited decompression run time.

In order to participate in this course you must be a TSD qualified diver with a minimum of 100 dives.