A PADI Assistant Instructor (AI) is the first instructor-level rating in the PADI system. It sits between PADI Divemaster and PADI Open Water Scuba Instructor (OWSI): a Divemaster who has completed the first part of instructor training and can now take on real teaching responsibility under an instructor’s supervision. In fact, every PADI Instructor becomes an Assistant Instructor on the way, because the AI course is the first half of the PADI Instructor Development Course (IDC).
That last part surprises a lot of people. Many divers assume you jump straight from Divemaster to Instructor. You don’t. This post explains what the Assistant Instructor rating actually is, how it compares to Divemaster, who should take it as a stand-alone course, and who should go straight into the full IDC.
Where the Assistant Instructor fits in the PADI pro ladder
Here are the professional PADI ratings up to Instructor, in order:
PADI Divemaster (DM). The first professional level. A Divemaster can guide certified divers and assist instructors on courses. With Two Fish the Divemaster internship runs over 4 to 6 weeks, with the option to train at two of our locations.
PADI Assistant Instructor (AI). A short course, typically 4 to 5 days, that takes a Divemaster into teaching. An AI can assist instructors with far more responsibility on courses and can teach the PADI Peak Performance Buoyancy specialty independently.
PADI Open Water Scuba Instructor (OWSI). The full instructor rating. An OWSI can teach PADI recreational courses up to Divemaster level. And here is the key point: the prerequisite for the OWSI course is the Assistant Instructor rating.
The PADI IDC packages both together. It runs over roughly two weeks and contains the AI component followed by the OWSI component, and candidates then sit the two-day PADI Instructor Examination (IE), which is run independently by PADI. Pass that and you’re a PADI Instructor.
Assistant Instructor vs Divemaster: what’s the difference?
This is the question we get asked most, so here it is side by side. The short answer: a Divemaster works with certified divers, an Assistant Instructor works with students.
| PADI Divemaster | PADI Assistant Instructor | |
|---|---|---|
| What it is | The first professional PADI rating | The first instructor-level PADI rating |
| Main role | Guiding certified divers and assisting instructors on courses | Teaching alongside an instructor, with real responsibility for students |
| Can teach independently | No courses (can lead some programmes for certified divers) | The Peak Performance Buoyancy specialty |
| Course length | 4 to 6 weeks (Two Fish internship) | 4 to 5 days |
| Prerequisite for | Assistant Instructor and the IDC | The OWSI component of the IDC |
| Best for | Divers who want to work in diving and guide | Divemasters who want to teach, or test the water before a full IDC |
Neither one is “better”. They’re different rungs on the same ladder. If your goal is to guide divers and work on a boat, Divemaster may be all you need. If you’ve caught the teaching bug, the AI rating is your next step.
Who should take the AI course on its own?
Because the AI component is built into the IDC, most people never take it separately. But you can, and for some divers it’s the smarter route:
You can’t take two-plus weeks off work. The full IDC plus IE needs a solid block of time. The AI course needs less than a week, and you can complete the OWSI component later.
You’re not sure teaching is for you. A stand-alone AI course is a low-commitment way to find out whether you enjoy standing in front of students before you invest in the full IDC.
Your Divemaster was years ago. The AI course rebuilds your theory and in-water standards before you face the IDC. (We also run a DM Experience Programme of up to 4 weeks before an IDC if you want supervised practice assisting on real courses first.)
You want to spread the cost. Splitting the training into two trips splits the investment too.
Who should skip it and go straight to the full IDC? Anyone who already knows they want to teach, has the time, and meets the prerequisites: at least 18 years old, a PADI Divemaster (or equivalent leadership rating with another agency), certified for at least 6 months, 100 logged dives with proof of deep, night and navigation dives, a current medical, and an Emergency First Response course within the past 24 months. If you tick those boxes, doing AI and OWSI back to back in one IDC is the fastest and most economical way through. If you’re not there yet, the stand-alone Assistant Instructor course is within closer reach: you can start it with 60 logged dives, the same number you need to certify as a Divemaster.
One thing worth knowing: if you arrive at an IDC already holding the AI rating, you repeat the AI component as part of the course.
Claire split her IDC in two. Here’s how it worked.
Claire took her Assistant Instructor course with us in March and returned for the OWSI component in October. In her words:
Realising I could break up the IDC was like a dream come true. I couldn’t take 2 weeks or more off from work and I was struggling to find the money to fund the full IDC. I had dived with Two Fish Divers in Bunaken many times and when I explained my situation to Nigel, he came up with an ideal solution: to take them as 2 separate components.
My Assistant Instructor course was conducted by Tina and it was incredible. I had real life “students” to work with under Tina’s guidance. I received the full PADI Instructor Crew pack during the Assistant course so there were no worries about me going rusty on the theory while I waited. From March to October I studied the crew pack and Instructor Manual weekly. I think I must have been one of the best prepared OWSI candidates ever!
The financial side was much easier too. Every month I paid an instalment to Two Fish, so when I arrived in Bunaken the course was paid for and I had a brain packed with Instructor knowledge. If I had to do it again now I’d do it in exactly the same way. Plus I got two diving trips out of it, not just one.
Doing your AI and IDC with Two Fish
We run IDCs throughout the year from three PADI 5-Star IDC centres in Bali: Amed, Nusa Penida and Sanur. Your Course Director is Restuning, the first female Indonesian PADI Course Director. She teaches in English, Indonesian and Dutch, runs optional morning yoga through the course, and as a freediving instructor she’ll give you a free intro to freediving session along the way. She’s on our permanent team, so you train with her directly rather than a freelance Course Director you’ve never met.
Our IDC comes with a 100% pass guarantee: if you don’t pass your IE, we provide extra training and a free IDC retake. After certification you can join our free instructor internship for up to 2 months of real teaching experience. And if you complete your Divemaster with us first, you save 10% on your IDC course fee, which is more than IDR 2,500,000.
Frequently asked questions
What’s the difference between an Assistant Instructor and a Divemaster?
A Divemaster guides certified divers and assists instructors. An Assistant Instructor has completed the first half of instructor training, takes on real teaching responsibility with students under an instructor’s supervision, and can teach the Peak Performance Buoyancy specialty independently.
Do I have to become an Assistant Instructor before the IDC?
You don’t need to take it as a separate course. The AI component is built into the IDC, so every candidate earns it on the way to OWSI. Taking it stand-alone is optional, and useful if you’re short on time or still deciding.
How long does the PADI Assistant Instructor course take?
Typically 4 to 5 days as a stand-alone course. As part of the full IDC, the whole programme (AI plus OWSI) runs over roughly two weeks, followed by the two-day Instructor Examination.
Can I split the IDC into two parts?
Yes. You can take the Assistant Instructor course on one trip and return for the OWSI component later, exactly as Claire did above. It suits divers who can’t take a long block of leave or who want to spread the cost. We can also arrange payment by instalments.
I did my Divemaster years ago. Am I ready?
Probably, with some preparation. The AI course itself refreshes your theory and standards, and we run a DM Experience Programme of up to 4 weeks before an IDC where you assist on real courses under one of our instructors. Get in touch and we’ll recommend the right route for your experience level.
What can I teach once I’m a full instructor?
A PADI Open Water Scuba Instructor can teach PADI recreational courses up to Divemaster level. Many of our candidates add the Master Scuba Diver Trainer (MSDT) prep after the IDC to teach specialty courses too.
Ready for the next step?
Whether you want the stand-alone Assistant Instructor course, the full IDC, or you’re still weighing up Divemaster first, we’ve helped divers through every version of this path for over 20 years. Start with our PADI IDC page for dates, prices and prerequisites, or browse the whole professional pathway on our Become a Dive Pro hub. Send us a message and we’ll work out the route that fits the time and budget you have.
We look forward to meeting you and diving with you soon in tropical Indonesia!
