The Million Dollar Question: What is the difference between PADI, NAUI and SSI?

What is the best scuba diving training organisation? PADI, NAUI or SSI?

This is the number one question asked by many beginners. There is no doubt that PADI is the most well known (the marketing is really good!), but the ultimate goal of all training organizations is the same: to train professionally responsible divers. The framework of teaching is all similar, and the accreditation is also up to international standard.

That is to say, if the dive centre you visit is PADI certified, your diving license of NAUI or SSI is also eligible, and vice versa. (No organization has the power to purchase the sea, alright?)

Next, let me explain why and how all diving organizations are similar, and the differences of PADI, NAUI and SSI respectively.

In fact, this question has been answered million times, so let's dive deep!