As long as there has been more than one agency providing scuba instruction and awarding certification cards (C-Cards), this debate has raged. Making the decision was a lot easier when the US Navy was the only game in town. Like many things, the answer to this question depends…
There are dozens of certifying agencies. The two agencies a new diver is most likely to come across are; the National Association of Underwater Instructors (NAUI) and the Professional Association of Diving Instructors (PADI). Many academic institutions (your local community college) are likely affiliated with NAUI. Your local dive shop is most likely affiliated with PADI. Less common is are Scuba Schools International (SSI), Scuba Diving International (SDI), Scuba Educators International (SEI) and the National Academy of Scuba Educators (NASE) among others.
Each of these will provide you with a recognized C-Card upon completion of their basic open water course. There is general recognition of each agencies certifications so getting your tanks filled at a shop that is SSI affiliated or going out on a dive charter, is not a problem with a PADI or SDI card.
NAUI is one of the oldest certifying agencies. They were founded as a non-profit in 1959.
PADI was founded in the 1960s and had a business model associated with it. They introduced the card with your picture on it. Today PADI is the behemoth agency. They are everywhere.
NASE affiliated dive operations are not too common, but they have received good reviews from those receiving their initial scuba certification.
When looking for a course there are several things you should consider; instructor reputation, class size, facilities, equipment and fees. I place reputation at the top of the list. For a new diver the quality of the instruction you receive comes down to the instructor and not necessarily the agency. Be wary of any instructor who says they are affiliated with, “all the agencies”. Most agencies offer an E-Learning option that you may want to take into consideration. If you decide to get certified through a resort or cruise ship program, this will most likely be a requirement.
Scuba is an inherently dangerous activity. It is very safe when done right, disastrous when it is not. When selecting your course, talk with those who have recently completed a certification and directly with an instructor, NOT a salesman.
What matters is that your initial instruction provides a solid, safety focused foundation. If you do not have confidence in the instructor and the program, move on. There are plenty others to choose from.
If you decide to continue taking courses past advanced divers courses and are looking at entering the professional ranks with a Dive Master certification (not be confused with “Master Diver”), you will need to look harder at the agencies to find what works best for you. The path to Dive Master, the first professional certification, is a slightly different with each agency. At this level insurance and other business related concerns come into consideration.
Let your diving adventures begin.