additional training
The learning should never end...
There's almost a course for every interest in SCUBA diving. Some of the additional courses available are:
Solo Diver
Drift Diver
Enriched Air Diver
Search & Recovery Diver
Wreck Diver
The benefits of continual learning is the refreshment of previously learnt skills, as well as updating any knowledge points that may have changed.
Additional qualifications have the benefits of demonstrating skill levels for insurance, allowing the diver to progress on a dive with confidence of coverage.