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. 

In your entry-level scuba course, you learned fundamental skills intended to promoted your safety and teach you how to deal with various problems that can arise during dives. To remain proficient in these skills, you must practice them. This is even more important if you are a relatively inexperienced diver. Most instructors and training agencies recommend a refresher course after a year of not diving.

If you have been out of the water for a prolonged period, consider retaking the entry-level course. You never know what you may have forgotten or missed in your original course. When undertaking refresher training, DAN highly recommends both the classroom portion (which includes basic dive physics and physiology as well as dive planning and execution using dive tables and computers) and the in-water skills portion.

Checking your equipment and doing a buddy check, regardless of how many times you’ve dived with your gear or with the same buddy, can help prevent many of the common factors that lead to dive accidents.

Divers are responsible for doing a proper buddy check, having a plan for
handling emergencies and making the decision to abort a dive if necessary.

This incident report stresses the importance of checking your equipment is working as designed.