Last Updated on December 14, 2021 by Dan

### What is the PADI IDC?

The Instructor Development Course (**IDC**) is made up of two parts – the Assistant Instructor (AI) course and the Open Water Scuba Instructor (OWSI) program. Most dive professionals complete the entire **IDC** and go on to attend an Instructor Examination (IE), which is the final step to earn a **PADI** Instructor certification. This process usually takes around 3-4 weeks and approx costs are around $1450, if already a Divemaster.

If you are looking for practise exam questions we recommend checking out the www.idc-guide.com for their full list of questions and purchase one of their revision packs that includes lots of **revision documents and 11 practice mock exams**, the exams include all the questions and answers you will need to revise to PASS the PADI IDC. Here are 5 sample questions (with the answers in bold) from IDC Guide website above:

**Constants used for Dive Theory Exams**

**Metric**

1 litre of salt water weighs 1.03 kilograms

1 litre of fresh water weighs 1 kilogram

Pressure increases by 1 ATM every 10 metres of salt water

Pressure increases by 1 ATM every 10.3 metres of fresh water

Pressure changes per unit of salt water = 0.100 ATM/m

Pressure changes per unit of fresh water = 0.097 ATM/m

**Physics**

1) What is the absolute pressure at 24m in sea water?

a) 2.4 atm

b) 22.75 atm

c) 2.28 atm**d) 3.4 atm**

2) What is the gauge pressure at 16m in sea water?**a) 1.6 atm**

b) 2.55 atm

c) 1.55 atm

d) 2.6 atm

3) What is the gauge pressure at 16m in fresh water?

a) 1.6 atm

b) 2.55 atm**c) 1.55 atm**

d) 2.6 atm

4) If a sealed, flexible air filled container with a volume of 17 litres at 19m of sea water is taken to 37m, what would the new volume be?

a) 21.56 litres**b) 10.48 litres**

c) 3.7 litres

d) 26.5 litres

5) If an object weighs 197 kg and displaces 16 litres, how much water needs to be displaced to achieve neutral buoyancy in 18m of fresh water?

a) 179.56 litres**b) 181 litres**

c) 265 litres

d) 289 litres