thoughts on an open water diver in a technical diving forum

[BlueTrin]

the weirdest thing about this is that I have a few in-person technical diver and technical diving instructor friends- and they're SO NICE. like they had absolutely no issues discussing deco theory with me and actually seemed super excited about sharing their passion. tbh, it seems like it's just people online with no balls that wouldn't dare say it to my face, but hide behind a screen.

Online interactions are polarised.

A lot of people will just read your post and don’t comment.

People are more likely to reply when they have a strong opinion (you won’t see many people reply to not add anything they feel worthwhile), so you have a bias in the replies.

 

[tursiops]

kaylee_ann, I'd much rather have someone who knows they are lacking knowledge in some area ask questions about it, than to have someone who is sure they already know everything post some really dumb stuff. As someone said earlier, there are no stupid questions, but wow are there some stupid answers!

 

[kaylee_ann]

It’s great to see enthusiasm and a thirst to learn. Your decompression calculation thread was very educational for us all.

Many of us enjoy delving into the theory of diving. That can be learned even if your skills are still developing.

oh I forgot to reply to this. thanks! yeah, I think there's some things people are like, I'm just gonna leave that for the computer LOL. no reason to learn it. so maybe someone will see that thread and realize they want to learn the calculations themselves too! a few posted some good formulas further down in it and even general decompression info.

 

[rhwestfall]

It is great you are pursuing knowledge. Asking questions along the way. I'd wonder if the hostility was because they couldn't explain it properly, so they get hostile. A frequent happening.

I'd like to see explanations. As others have said, help out or move on.

Keep asking, keep learning. We all can learn a bit more!

 

[kaylee_ann]

kaylee_ann, I'd much rather have someone who knows they are lacking knowledge in some area ask questions about it, than to have someone who is sure they already know everything post some really dumb stuff. As someone said earlier, there are no stupid questions, but wow are there some stupid answers!

oh yeahhh there's way too many people who think they know what they don't know.
even recreational divers, they think "oh I have my basic skills down, some diver showed me how to do air switches/tank switches (whatever the hell you call that) so I can go dive to 200 feet". and those same people, they certainly descended to 200 feet, but never ascended to the surface.
funniest (not funny, but ironic I guess?) part is, it's almost always new open water divers. I think that's why people assume the worst when I ask this stuff

 

[BlueTrin]

yeah, I've tried that. unless I say it 5+ times, it seems like everyone ignored it, even when it was at the top of the post. nobody has any damn reading comprehension LOL, they get mad immediately. they only see what they want to see.
on my calculation question I must've said at least 5 times I'm not going to use this for actual dive planning, I'm not a tech diver, I'm just curious...
literally every time I use gradient factors for any random planning, it's always 75/95. and every time I do, I have to put 10+ disclaimers on the post saying it's just for fun, I don't ever plan on using these.

People have a low attention span, they will read the last few posts and comment. They won’t see or remember your warning a few posts ago. There is no solution to that: you can just ignore the irrelevant bits?

For the gradients factors, people usually use what works for them, there is no exact rule (except in some agencies).

People used to use a low value for the first value (GFlo) but then the recent trend seems to indicate that maybe deep stops aren’t so good, so people use higher GFlo now (again that’s not everyone but a trend)

For GFHi, i know that at my range people often use something between 75 and 85.

100 means 100% do the original Buhlman procedure.

The algo uses GFLo for the first stop and GFHi for the last (or surface I can’t remember) then draw a line to interpolate in between.

I’ll try to find a picture that explains it better (I think there was a cool one from the Shearwater blog)

(Bear in mind I am a newbie/baby technical diver)

 

[kaylee_ann]

It is great you are pursuing knowledge. Asking questions along the way. I'd wonder if the hostility was because they couldn't explain it properly, so they get hostile. A frequent happening.

I'd like to see explanations. As others have said, help out or move on.

Keep asking, keep learning. We all can learn a bit more!

yeahhh. or they're irritated that it took them forever and a day to get it, meanwhile I'm learning before I even do AOW. that's not bragging or being cocky/arrogant, I'm just starting earlier than they did.

I think it's the same situation for those who get mad even when I'm occasionally right.

 

[BlueTrin]

This is the one:

Surface GF and Other Teric Musings - Shearwater Research

Powerful yet Small Imagine having a tool that would give you a numerical percentage value of the decompression stress you would encounter if you were to instantaneously ascend to the surface. Not all dives are […]

www.shearwater.com

So if you look at the cool graph, it is showing how you get the 30/80 line, the decompression starts from the top right:

• Moving left on this graph means that you ascend
• Moving down means you are decompressing and having less inert gas in your body
• You need to be above the ambiant pressure line to decompress (under you off gas)
• The m value line is the line that represents 100/100 Buhlman (i.e. if you wanted to do 100/100 Buhlman, you’d start your stops on that line)

 

[kaylee_ann]

People have a low attention span, they will read the last few posts and comment. They won’t see or remember your warning a few posts ago. There is no solution to that: you can just ignore the irrelevant bits?

For the gradients factors, people usually use what works for them, there is no exact rule (except in some agencies).

People used to use a low value for the first value (GFlo) but then the recent trend seems to indicate that maybe deep stops aren’t so good, so people use higher GFlo now (again that’s not everyone but a trend)

For GFHi, i know that at my range people often use something between 75 and 85.

100 means 100% do the original Buhlman procedure.

The algo uses GFLo for the first stop and GFHi for the last (or surface I can’t remember) then draw a line to interpolate in between.

I’ll try to find a picture that explains it better (I think there was a cool one from the Shearwater blog)

(Bear in mind I am a newbie/baby technical diver)

must be a really low one since the warning is in the beginning of the post itself LOL. usually people remember what is bad to them before what is good or neutral.

I guess it's because 75/95 isn't very conservative, relatively risky in fact if I'm understanding right. If I'm getting it right, you surface at 95% of the way between the line where your leading tissue has your desired pressure gradient (75% of that M-value) and the actual M-value line. Which is your maximum saturation level (ETA- Deco for Divers calls this part 'supersaturation'). After that I believe you go into critical supersaturation (ETA- yeah, book confirms this- you go into critical if you exceed that M-value).

Basically you're really close to being right on that line. If you mess up really any part of your deco, you could exceed it. Pretty big risk for getting bent. A friend of mine said his friend dives 95/95 on every dive, and has been bent God knows how many times. But....he hasn't changed a thing.

 

[BlueTrin]

So about the link I posted: the ambiant line is the equilibrium, if you stay at the same depth, your tissues will off-gas/on-gas and move your vertically towards the ambiant line.

The space between the gradient factor line and the ambiant pressure line, is the safe space where you’ll decompress.

Ideally, you’d want to be on the gradient factor line as it is the safe point the furthest from the ambiant line, so you’ll decompress faster.

However you move by steps because it’s easier to hold fixed depth stops, so you move to the next stop when the next stop is under the gradient factor line with your current tissues loading.

Hope that helps a bit …