A potential scuba diver should go to a certified dive center or a dive instructor. You can find a dive center near your hometown from the link below:

Dive Center Finder

The dive center you have applied will have a diving agency (system) that they will offer you. (Read the article; How to start scuba diving). And your journey will begin…

The scuba diving first level course (generally, you gain a certification at the end and can be able to dive up to 18 meters with a dive buddy/leader, depending on the diving system you’ll be in) lasts for 15-24 hours in total. There are 3 main stages in scuba diving training.

Academic Session

In this session, student divers learn the basics of scuba diving. The lesson takes place in a classroom, generally supported by a video, manual, white board, power point presentations and ofcourse, a certified scuba instructor. Student divers learn about the diving environment, the equipment and usage, dive planning, affects of increasing and decreasing pressure and such. There might be quizes and a final exam.

Confined Water Dives

There you are at last! The academic session is over and you are about to scuba dive. You’ll not forget your first breath with scuba. In confined water training dives, you should be at most 5 mt of depth. This is both for your psychological and physical safety. Here, you are learning some skills. These skills are the simulations of potential events in your dives. This can be clearing water out of your mask without surfacing or finding and replacing your regulator (the unit that a scuba diver breaths from) when the it goes out of your mouth somehow (a diver in front of you may kick his/her fin accidentally). In confined water dives, the instructor is demonstrating (showing) the skills first.

Open Water Dives

At last! You have completed’em all! An open water dive means that you are diving deeper than 5 meters. In open water dives,  student divers repeat almost all the skills that they have learned in confined water dives. The idea is to master these skills. Two differences between confined water dives and open water dives are:
In open water dives, the instructor doesn’t demonstrate. Instructor only gives the signal of the skill and waits the student diver to perform the skill.
An open water dive cannot be in shallower than 5 meters.

Generally, a student diver should attend at least 5 dives in total, depending on the diving system.

Before every dive -regardless of open water or confined water- the instructor gives a briefing about the dive (organisation of the dive, max depth, dive time, skills and etc) and a debriefing after the dive (the mistakes and the solutions in performing the skills, forexample).

When you complete these 3 steps, you are becoming a certified scuba diver. The name of the certification will be “Open Water Diver” in both PADI and SSI, “1* Diver” in CMAS.

Your diving certification is just like a driving license. To be able to scuba dive, you must have one. Almost in every country, the local cost guards check for divers’ certification. Besides, this certification is a “must” for a safe and comfortable dive. Don’t forget that diving would be very dangerous without taking a course and may cause very bad consequences. Dive responsibly.