282
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
this post was submitted on 15 Apr 2024
282 points (94.6% liked)
Ask Lemmy
26734 readers
1465 users here now
A Fediverse community for open-ended, thought provoking questions
Please don't post about US Politics. If you need to do this, try !politicaldiscussion
Rules: (interactive)
1) Be nice and; have fun
Doxxing, trolling, sealioning, racism, and toxicity are not welcomed in AskLemmy. Remember what your mother said: if you can't say something nice, don't say anything at all. In addition, the site-wide Lemmy.world terms of service also apply here. Please familiarize yourself with them
2) All posts must end with a '?'
This is sort of like Jeopardy. Please phrase all post titles in the form of a proper question ending with ?
3) No spam
Please do not flood the community with nonsense. Actual suspected spammers will be banned on site. No astroturfing.
4) NSFW is okay, within reason
Just remember to tag posts with either a content warning or a [NSFW] tag. Overtly sexual posts are not allowed, please direct them to either !asklemmyafterdark@lemmy.world or !asklemmynsfw@lemmynsfw.com.
NSFW comments should be restricted to posts tagged [NSFW].
5) This is not a support community.
It is not a place for 'how do I?', type questions.
If you have any questions regarding the site itself or would like to report a community, please direct them to Lemmy.world Support or email info@lemmy.world. For other questions check our partnered communities list, or use the search function.
Reminder: The terms of service apply here too.
Partnered Communities:
Logo design credit goes to: tubbadu
founded 1 year ago
MODERATORS
Another hobby, though I haven't been in a few years is SCUBA diving. I learned how to dive under people who took all of the safety limits and procedures quite seriously. I was always diving in a pair with a person I knew, and we always had a comfort level of communication and teamwork based on familiarity with each other.
I left that constant diving life, and later to scratch the diving itch I decided to go do a recreational dive in the US. I showed up to the place and got on the boat. On the ride out to the dive site, I was expecting a pre-dive meeting where details would be gone over, and I'd be assigned my partner so we could interact at least a little bit before getting in the water. That never happened. I was waiting and waiting for the meeting to start when the boat just stopped, the people running it announced we were at the dive spot and just started pointing to pairs of people to be "partners" basically as they were jumping off the boat. I'm used to doing an equipment shakedown with a partner, but my assigned partner was some guy who just hopped in the depths and was gone before I could do any of that.
This was a simple dive to a flat sand bottom. People were mostly looking for trinkets down there. That said, the lack of organization was shocking. When time was up, people just started shooting to the surface. Nobody else was doing safety stops on the way up, and because of me doing it I was the last person out of the water. It was very scary sloppy and I did not go back to any open-to-the-public recreational dives after that.
Thats terrifying, especially given that the ocean is potentially more dangerous than space. the power of water is not to be underestimated
It was really scary. I'd shadowed some recreational groups before to help out with the shop I'd been close with and a reoccurring theme would be that customers who dived for maybe one week a year were so caviler about safety because they were "very experienced", while the people who dived so much they were having to calculate their weekly limits were abundantly respectful of the depths.
As one person working there would say, "You never get a brain aneurysm until you do."
Can you explain what the weekly limit is about? I know very little about scuba.
There's a lot of biology involved that I don't understand the intricacies of, but basically the more time and at more depth you are underwater the more your body is dealing with changes in the density and makeup of your blood. You need time on the surface to normalize. For a similar reason you need to do safety stops to allow your body to adjust to the changes.
For normal recreation dives, it's pretty simple that people are limited to (IIRC) two dives/two hours per day as a general guideline. Once you get into deeper dives, using different breathing mixes, and other stuff people have to start doing a little bit of double checking to make sure they don't overdo it.
I'm not sure about the weekly limit, but I guess it has also to do with the absorbtion of nitrogen into your blood, which is why you make safety stops after going deep and why there are daily limits.
Depending on how deep and how long you dive, more nitrogen will get dissolved in your blood due to the increased pressure. It stays there until you get into lower pressure ( ascending to the surface). If you do that too fast, the nitrogen will build up bubbles. And bubbles in the bloodstream is really really bad, hindering the flow of blood. Doing safety stops in lower depths gives some nitrogen the time to leave your body through the lungs while breathing. Not diving for a certain time after your dive sessions will give time to release all additional nitrogen from the blood, preventing a builtup over each dive.