Diving requires special skills learned during training and maintained through practice. “Use it or lose it” is especially true in diving. While skills will degrade somewhat with as little six months of inactivity, most dive educators and instructors consider inactivity of one to two years sufficient to warrant refresher training.

With longer periods, you’ll want to consider how much you have changed and what changes have taken place in the diving world. After a long hiatus, we highly recommend formal review of both your knowledge and in-water skills before you resume diving. 

The classroom portion of refresher training generally covers:

• Dive planning
• Use of dive tables and computers
• Other knowledge and theory per your training agency’s standards 

For your first dive after a period of inactivity:

• Do not dive alone. Consider diving with a divemaster or instructor
• Dive at a familiar site
  • Shallow
  • Minimal or no currents
  • No major hazards
  • Choose a site that is not remote

Practice your skills in confined water before you dive in open water. Good skills to practice include:

• Predive checks
• Buoyancy checks (proper weighting)
• Buoyancy 
• Mask clearing
• Mask removal and replacement
• Recovering and clearing your regulator
• Shared air ascent
• Emergency swimming ascent or controlled emergency swimming ascent (depending on what your training agency teaches)

Take a continuing education course at the level recommended by your training agency.