PADI Instructor Course and Instructor Exam - Tanks and Valves, Equipment of Diving 

Thanks so much for these!

As always, another outstanding video, thank you so much for making these videos

Thanx for your effort. It really helps.

Thanks for the information!

good video. I have a question; hence we got 5% more displacement after the hydro test, would this means that we have a little growth every time we have the test done