I love diving or ambient pressure diving, you become directly exposed to the pressure of the surrounding water, it is thrilling!
I've never done that but I have always wanted to learn! 
My favorite is scuba diving, where you use the self contained breathing apparatus to go even deeper.
That's what I always wanted to do on the great barrier reef. I bet it would be beautiful.
The technology of underwater diving actually started with stone weights tied to a person to make a fast decent. One of my favorite things to do.
That sounds scary! I'm glad it's not that dangerous nowadays!
There are all kinds of new technology for people afraid of the danger like crewed submersibles that extend diving range even further that can be really fun as well.