How to ACE the PADI IDC Physics exam!

It’s surprising how comforting it is when you break down the PADI IDC Physics exam subjects into ones that you know and ones that you need to brush up on.

How to ace the PADI IDC phyiscs exam!

First, make sure you understand the basics of physics.

This may seem like a no-brainer, but it’s important to have a strong foundation before you can apply the concepts to diving.

Next, familiarise yourself with the different topics.

One step at a time! 

Finally, practice, practice, practice.

The more questions you work through, the better prepared you’ll be for the exam.

Breaking physics down to small steps

Diving is all about physics.

To ace your physics exam on your PADI Instructor Course, you need to understand the basics of a few concepts.

On My Online IDC Preparation Course, I’ve broken down these topics to: 

1. Calculating pressures underwater

You’ll need to understand the difference between: 
Guage Pressure and Absolute Pressures in both Fresh and Salt water.

2. The Effects of pressure

Every diver naturally understands that air spaces get smaller as pressure increases. 
However, when you’re sitting in front of an exam answer sheet, sometimes that knowledge disappears! 

3. Pressure volume relationships

To be honest, this is virtually the same as calculating pressure underwater, but it’s a good idea to understand the relationship between the two. 

4. Solution of gasses into liquid

This is Henry’s Law. 
It’s all about how nitrogen gets absorbed into our blood stream, and why bubbles form when we ascend. 

It’s closely related to a lot of Physiology questions regarding decompression illness. 

5. Light

This is where we talk about refraction, and why objects look bigger through our masks.

6. Displacement

This is one of the few subjects that isn’t covered on the PADI Divemaster course. 

You’ll need to calculate how much air to add to a lifting bag in order to bring an object to the surface. 

7. Sound

Speed travels slower through water than in air. 
It makes it tricky to determine where noise is coming from. 

8. Heat

Heat leaves our body faster in water than in air. 

PADI IDC Physics - Test yourself right now!

To get an idea of where you stand right now, take a look at the: 
PADI IDC Physics – test your knowldege  page. 

Find out where you need to brush up.

If you want more questions, you can buy 5 Full Sets of PADI Mock IE Exams for US$ 49
Each of the 5 mock exams is very similar to the written exams that you’ll find on the 2023 PADI Instructor Exams.

Full Set

By understanding these physical principles, you’ll be able to better explain how diving equipment works and how to use it effectively.

You’ll also be able to more easily troubleshoot problems that may arise while diving.


More importantly, you’ll be able to ACE the Physics Exams!

However, don’t worry if you’re not a natural at physics. With a little study and practice, you’ll be able to master the material and earn your instructor certification in no time.

Key concepts in the physics section of the PADI IE

The old science boffins!

Have you ever wondered how those old scientists knew about Scuba Diving?  The people that come up with: 

Boyles law, or Henry’s law, or Charles’ law, or Dalton’s law?

They must have been geniuses!

Or maybe they themselves just had a good scuba instructor.

Don’t worry! You don’t need to be a genius in physics to become a PADI Instructor.
But, whether or not you’re interested in the ancient scientists, it’s a good idea for you to get confidence in the basics if you’re going to be teaching people how to dive. 

Tips for studying for the PADI IDC physics exams

The physics section of the PADI Instructor Exam can be daunting for even the most experienced divers.

After all, who wants to think about pressure volume relationships, or absorption of gas into liquid when they could be relaxing on a sunny beach? Or diving with their friends? 

However, there are a few simple tips that can help make studying for the physics section a little bit easier.

First, find a plan, find the path that you want to take for success. 
Where you can work at your own pace, and you’re confident with the process. 

Second, find a buddy to study with. Help each other. 

In addition to providing motivation, a study partner can also help to clarify concepts that are giving you trouble.

And vice versa. It’s surprising how much more you learn when you start to explain to others.

Finally, don’t forget to take practice exams. (lots of them).

By becoming familiar with the format and content of the test, you’ll be better prepared come exam day. 

I have another page on this site which concentrates on some Physics Questions.

The page isn’t only questions, there are some tips, some help and videos leading to the questions. 
Take a look, it might help. 

If you’re studying for your Divemaster Exam, it would be wise to take a close look at chapter 9 in your Divemaster Manual. 

The same is true if you’re studying for your PADI IDC or PADI IE. 

But be careful! Divemaster level Physics isn’t quite the same as Instructor level. 

There are a few extra subjects, so be sure to make sure that you’ve filled in any gaps. 

How can I help you?

I can help with as little or as much help as you need. 
Here we go from FREE working through the options. 

1. Free Videos

You’ll find some FREE videos here: 
AND if you like them, – well maybe you’ll buy me a coffee?

2. Mock exams

Practice, Practice, Practice. 
Loads of questions. All similar to the ones that you’ll find on your final exam.
– Low cost, perfect to prove to yourself that you’re all up to speed! –

Click HERE for all FIVE mock exam papers for US$49 (or equivalent in your currency

3. Online Theory and Standards

ALL of the above mock exams. 
PLUS a lot more. 
61 lessons   

Videos, followed by questions to check your knowledge. 
Everything that you’ll need to pass your PADI IDC. 

Work at your own speed.
Over 700 questions in all!

plus of course, all of the answers!

Click here for PADI IDC Theory and Standards Preparation course

PADI IDC theory

4. Online FULL preparation Course

Everything. I MEAN everything! 
– In my opinion, by FAR the best value for money -.

The WHOLE of the Dive theory  Preparation course 
How to teach in the pool
Briefings, debriefings etc.. 
How to organise lessons. 
How students learn,

lots of psychology. 
Loads of tips to make you a brilliant instructor (and pass your PADI IDC!)


Click here for Full IDC Preparation

5. Distance Learning

This is where I am your
“Learning Buddy!”

I drip feed the Mock Exams to you one by one. 
You send me your answers via email, and I mark them. 

I give tips, advice and general help, then send you the next set of exams. 

I’ve been helping hundreds of people with distance learning over the past 20 years. I update the papers every year, so they’re always current. 

Click here for Distance Learning

Good luck!

There is more advice for preparing for Theory Exams here:
Dive Theory for PADI Instructors

I hope that these tips have helped you prepare for the physics section of the PADI Instructor Exam.

Remember, with a little preparation and practice you can ace this section!

Good luck and happy studying!

Last modified: 10th January 2023
Author: Steve Prior