A logical method for dealing with fear in diving that relies on understanding the causes and dealing with them rationally.
Fear is a logical response to the unknown. Understanding this unknown turns fear into respect.
Its cause is the unknown, not the actual danger. The depths you train in are safe by their rules. Know the rules and the fear changes.
Study the creatures before diving. Anyone who knows that a reef shark does not attack fears it less.
Ignorance inflates fear, and knowledge adapts it into healthy respect.