I saw (2) submits being up-voted or got plenty comments here on HN about caves and diving them. I do make a living as an "hacker" or "engineer" what ever you like to call it. But my passion is diving. Me and my business partner actually working on a start up focused on that sport. For myself the recreational sort of diving became less challenging for several reasons over time. Now I do caves and/or very deep dives mostly into caves or wrecks. I just uploaded some of my videos to YouTube (https://www.youtube.com/channel/UCB-fZxXha894oN8gPjS_VdA). I had them on my Vimeo (https://vimeo.com/user3271006/videos) channel only before. I found the comments about these stories (https://news.ycombinator.com/item?id=11658110) very interesting. I'm still transferring some of the videos from Vimeo to YouTube. AMA.