Becoming a scuba instructor sounds like a long jump from your last dive, but the people who succeed on an Instructor Development Course (IDC) are rarely the ones with the most dives or the strongest swim. They are the ones who arrived prepared: rested, organised and already thinking like teachers. This roadmap covers what to sort out before you sign up, how to use the weeks before the course, and what to expect once you are in the water and the classroom.
It is written for divers who already hold a professional-level certification and are weighing up a PADI IDC Gili Trawangan programme or a PADI Instructor Course in Indonesia more broadly, though it will also help anyone planning a long-term career in diving. Requirements and schedules are set by PADI and by each centre, so treat this as a practical guide rather than a rulebook, and confirm current details with the people running your course.
What an IDC Actually Is (and What It Is Not)
The IDC is a training programme that teaches you how to teach. It is not a course to make you a better recreational diver, and it is not an exam you can cram for in a weekend. Over a number of days you work through the PADI teaching system: standards and procedures, risk management, how to run knowledge development sessions, and how to organise confined water and open water lessons.
The programme has two levels, Assistant Instructor and Open Water Scuba Instructor. After the IDC comes the Instructor Examination (IE), which is run by PADI Examiners rather than by the centre that trained you. Keeping the two apart in your mind helps. The IDC is where you learn and practise; the IE is where you show what you have learned. Passing does not guarantee a job, but it opens the door to one. Candidates often arrive expecting a test of diving ability, then discover that explaining and organising matter just as much as demonstrating.
Check the Prerequisites Before You Pay Anything
Typical Requirements
Prerequisites vary and are updated from time to time, so look them up directly with PADI or ask the centre in writing. In general you can expect requirements such as a minimum age, a Divemaster-level certification or an accepted equivalent, a minimum number of logged dives, current first aid and CPR training, and a medical statement signed by a doctor within the past year.
Paperwork to Gather
The medical form is the item people most often leave too late. It needs a doctor’s appointment, and if a condition needs further assessment you want to know that weeks before you travel, not on arrival. Gather your certification cards, logbook and training records into one folder, digital and paper, and check the expiry dates on anything time-limited. Turning up without the right paperwork can cost you days. If something is missing, such as a first aid refresher, book it now. Most gaps can be fixed in a few days if you notice them early, but fixing them in the middle of an intensive programme is stressful and sometimes impossible.
Make Your Dive Log Work for You
A logbook is more than a number. Instructor candidates are expected to be calm, controlled divers, and a varied history helps: different sites, different conditions, different equipment and different buddies. If most of your dives were on the same reef in the same weather, use the weeks before the course to broaden that.
Treat these dives as practice rather than sightseeing. Work on holding a neutral hover without sculling, moving slowly, and keeping an eye on your buddy and your gauges. Write legible log entries with accurate details, because an instructor reviewing your experience will notice sloppy records. If you can, dive with someone who will honestly critique your trim and finning, since small habits become obvious when you are demonstrating to students. Keeping a short note of what went well and what to fix after each dive turns practice into steady progress.
Set a Realistic Timeline and Budget
Plan Your Time
Work backwards from the date you want to finish. Add up the months you need for medical checks, paperwork, extra diving and study, then add a buffer for delays such as travel disruptions or a slow start to your fitness plan. Many candidates underestimate the time between deciding to become an instructor and actually starting the course.
Plan Your Money
Money deserves the same honesty. Beyond the course fee, think about accommodation, food, materials, certification and examination fees, insurance and the cost of living while you are not earning. Ask the centre for a written list of what is included and what is not, so there are no surprises halfway through. Keeping a small reserve means you can say yes to a good opportunity, such as extending your stay to assist on a course, without financial stress. A calm plan on paper makes the actual training far more enjoyable.
A Simple Preparation Timeline
A simple timeline keeps the whole process manageable. Adjust the weeks to suit your own schedule.
| When | Focus | What to do |
|---|---|---|
| 12+ weeks before | Paperwork | Confirm prerequisites, book your medical, arrange any first aid refresher |
| 8 to 12 weeks | Experience | Dive in varied conditions, keep detailed notes, find a buddy who gives honest feedback |
| 4 to 8 weeks | Theory | Review each topic aloud, practise dive planning, read your course materials |
| 2 to 4 weeks | Skills and fitness | Film your skills, swim regularly, rehearse short briefings |
| Final week | Logistics | Pack documents, confirm the schedule and payments, rest well |
Choose Where You Will Train
What to Look For
The place you train shapes your whole experience. Look at how long the centre has been running IDCs, how many candidates it takes at once, who your course director and staff instructors will be, and how the Instructor Examination is organised. Ask whether you will be taught alongside real students, because watching experienced instructors work is one of the best parts of the programme.
Conditions matter too. Many candidates are drawn to the Gili Islands because the area combines warm water, short boat rides and a large community of working dive professionals. Easy access to dive sites means more of your day is spent practising, not travelling. Consider practical details as well: where you will sleep, where you will eat, whether the centre teaches in your language, and how far everything is from the dive centre when you are tired at the end of a long day.
Questions to Ask Before You Commit
- How many candidates are in each IDC group, and who teaches them?
- What is included in the fee, and what is paid separately?
- When and where is the Instructor Examination held?
- Will I get practice with real students or only with other candidates?
- What support is there if I need extra practice on a topic?
Refresh Your Theory Before Day One
You studied dive theory at Open Water and again at Divemaster level, but an IDC expects you to explain it clearly to others. Spend the weeks before the course revisiting physics, physiology, equipment, the underwater environment, and dive planning with tables or a computer. Do not just reread notes. Close the book and explain each topic aloud as if to a nervous beginner.
Flashcards, practice quizzes and a study partner all help. When you find a topic you cannot explain simply, that is the one to study harder. Also read the training materials you will use during the course, so the vocabulary is familiar from the first session. Arriving with solid theory frees up your energy for the new material, which is how to teach rather than what to know.
Make time for the practical side of theory as well. Plan a few sample dives on paper, work through repetitive dive scenarios, and talk through what you would do if the plan changed. Instructors are expected to think ahead, spot problems early and make sound decisions on behalf of students, so the more you rehearse these situations, the more natural it feels when a real class does not follow the script.
Practise the Skills Until They Look Effortless
Aim for Clarity, Not Speed
During the IDC you demonstrate the skills taught in entry-level courses to a high standard. The goal is not speed but clarity: each step slow, deliberate and easy for a student to copy. Mask clearing, regulator recovery, buoyancy control and emergency skills all need to be smooth, and your position in the water matters, because students must be able to see what you are doing.
How to Practise
Practise with a patient buddy or film yourself in a pool. Watching the footage reveals rushed hands, drifting depth and unclear signals that you cannot feel from the inside. Break each skill into steps, say them out loud as you demonstrate, and repeat until it feels boring. Boring is good. It means you will have attention left over for the student in front of you.
Smooth Transitions Between Skills
Pay particular attention to the transitions between skills. New instructors often demonstrate each exercise well, then lose control of buoyancy or position while moving on to the next one. Practise the whole sequence from start to finish, including how you gather the group, how you signal what comes next, and how you check that everyone is comfortable. Smooth transitions make a class feel organised and calm, and they show examiners and students alike that you are in control of the session.
Learn to Teach, Not Just to Perform
Briefings That Work
Strong divers sometimes struggle on an IDC because teaching is a different skill. A good briefing has a clear order, explains why a step matters, and checks that the student understood. Practise giving short talks on simple topics to friends or family who know nothing about diving, and ask them what was confusing.
The Human Side of Instruction
You will also practise handling the human side of instruction: a student who is anxious, one who is overconfident, one who learns slowly. Think about how you would adapt without making anyone feel judged. Expect feedback after every presentation and treat it as a gift. Candidates who listen, adjust and try again usually improve far faster than those who defend their first attempt. Flexibility is part of the job, because real classes rarely go exactly to plan.
Practising Your Presentations
Presentation skills are built the same way as diving skills: through repetition and honest feedback. Record a short practice talk on your phone, watch it back once for content and once for delivery, and note one thing to change. Do this several times before the course and you will walk in with habits that many candidates only develop halfway through.
Look After Your Body and Your Energy
IDC days are long, mixing classroom sessions, pool work and open water. You do not need to be an athlete, but a reasonable level of swimming fitness makes everything easier. In the weeks before you arrive, swim regularly and build up the time you can stay in the water comfortably.
Once the course starts, protect your sleep and hydration, use sun protection, and be careful with late nights. Pay attention to your ears and sinuses, since a blocked ear can sideline you for days. It also helps to keep your schedule free outside the course, so you are not trying to juggle work, travel and study. Rest is part of training, and tired candidates make avoidable mistakes in both teaching and safety. Eat properly, too. Long days without proper meals leave you foggy in the classroom and slow in the water.
After the Course: The Exam and the First Job
The Instructor Examination
The Instructor Examination is the formal assessment of what you learned. Approach it as a structured version of what you have already practised: theory exams, teaching presentations and skills. Go in rested, keep your preparation calm, and remember that examiners want to see safe, clear, organised teaching rather than perfection.
Your First Season
Afterwards, be realistic about getting started. Many new instructors begin by assisting on courses, guiding certified divers and building experience before leading their own classes. Extra languages, specialty ratings and a friendly attitude all make you more employable. Keep learning, stay in touch with the people you trained with, and treat your first season as an extension of the IDC rather than the end of it. Stay curious as well. The best instructors keep refining how they explain things, and they never stop being students of the sea and of teaching itself.
It also helps to think about the kind of instructor you want to become. Some people love teaching first-time divers, others prefer professional-level training or specialty courses. You do not have to decide immediately, but noticing what energises you during the IDC gives useful direction for your first season.
Key Takeaways
- The IDC teaches you how to teach; the Instructor Examination is a separate assessment run by PADI Examiners.
- Confirm prerequisites and paperwork early, especially the medical statement and first aid training.
- Use the weeks before the course to dive in varied conditions and refine your trim and buoyancy.
- Refresh theory by explaining it aloud, not by rereading notes.
- Practise skills slowly and film yourself so you can see what students will see.
- Protect your sleep, fitness and health during the course so you can learn at your best.
Frequently Asked Questions
How long does an IDC take?
It is commonly around ten days, with the Instructor Examination taking a couple of days more, but schedules differ between centres. Ask for the exact timetable before booking so you can plan travel and time off. Candidates who arrive rested and organised tend to find the pace more manageable.
Do I need to be a Divemaster first?
You generally need a Divemaster-level certification or an accepted equivalent. Check PADI’s current requirements, because the details can change and depend on your background.
Is the exam part of the IDC?
No. The Instructor Examination is a separate event run by PADI Examiners. Most centres prepare you for it during the IDC and can tell you where and when it takes place.
Can a beginner go straight to the IDC?
No. The path runs through Open Water, further training, Divemaster and a stretch of real diving experience. Each step builds skills you will rely on as an instructor.
How should I prepare physically?
Focus on comfortable swimming fitness, good sleep and healthy ears. You do not need elite athleticism, but you should be able to handle several long days in and around the water. Regular swimming in the weeks before the course is usually the most useful preparation.
Final Thoughts
Instructor training sits on top of professional-level diving, so if you are still deciding how to get there, the next article in this series is From Certified Diver to Pro: A Divemaster Training Guide for the Gili Islands.
Preparing for an IDC is mostly about habits: tidy paperwork, varied diving, clear explanations and enough rest. None of it is glamorous, but together it separates candidates who scrape through from those who enjoy the course and finish with confidence. Start early, ask questions, and give yourself time. The reward is a qualification that lets you share something you love and help other people feel at home underwater.