What do PADI, SSI, NAUI mean?
In order to become a Certified Scuba Diver in Honduras, you must be taught by an instructor who is licensed by a recognized Scuba Certification Agency in order to obtain a C-card (certification card). Currently, there is no single regulatory agency that oversees scuba training. In fact, there are over 60 scuba diving certifying agencies worldwide, such as PADI, SSI, NAUI, CMAS and so on! So how should you choose?
Visit your local shops. These are the people who you will be visiting for advice, repair, instruction, etc. The people you will be dealing with are more important than the scuba diving certification agency they represent.
Each agency has a mission. Some are focused on recreation, others on technical aspects, and some on education. All are trying to market their way as the best. Overall, regardless of which agency you end up diving with, you will learn to dive safely, and that is the most important aspect. Again, choosing your instructor is more important than the shop or scuba certification agency as a whole. Your comfort level will determine your overall diving certification experience.
If looking to obtain your scuba diving certification abroad, the same level of comfort should apply; however, you will only be with the dive instructor for the extent of your vacation or holiday. Choosing any of the larger agencies is a good option if you have no time to investigate, but still be sure to meet with your diving instructor ahead of time.
PADI is the international leader in certifications due to a large marketing campaign and funding. Other global agencies are SSI, NAUI, and CMAS. Some agencies are specific to certain areas (BSAC and LA County), others are non-profit, and some are for-profit. Most dive operators will recognize the certification from one of the larger agencies. Some may not be familiar with the smaller ones, so if you plan to dive around the world, you should check with the dive operator in advance to let them know your certification is from a local agency, and see if there are any additional requirements, such as providing a logbook or other proof of diving.