[callahad]

For me, it was the challenge and allure of doing something relatively difficult and rare. The first time I saw a Stop - Prevent Your Death sign[0] at depth, I knew I wanted the training to go beyond it.

It's also really peaceful underground.

Amusingly enough, I can't handle blue-water or wall dives (vertigo), nor wrecks (those aren't supposed to be there!), but caves are no problem. You've got walls, floor, and ceiling as a frame of reference, and everything is nice and cozy. It's like the Earth is giving you a hug.

[0]: https://commons.m.wikimedia.org/wiki/File:Vortex_Spring_cave...