Safety Stop Thoughts...

[namerg]

What do your class materials say? For purposes of the class... go with that as the right answer.

It is part of the literature nor a question.

 

[AlexL]

Wish I could remember where I recently read it, but it seems that with no stop there is a fair bit of silent micro bubbling, with a 3 min stop a small amount of micro bubbling, and with a 5 min stop none - almost none. Of course all this applies to dives within NDL. [...]
Not what he is saying. Deep stops aren't for shallow dives. Say you are diving at 100'. The deep stop is at 50' for 1 minute, then do your full SS at 15'.

the research that everyone seems to reference is from is a DAN international study done back in 2004. https://www.diversalertnetwork.org/default.aspx?a=news&id=514

the profile was back to back dives to 80'/25m for 25 minutes. surface interval was 3.5 hours. profile that resulted in the lowest bubble score was a 30'/10m per minute accent to a stop at 45'/14m for 5 minutes, along with another stop at 15'/4.5m for 5 minute. worst score was a 10'/3m per minute linear ascent with no stops. none of the profiles tested resulted in clinical DCS; they did not report on sub clinical DCS.

just got back from a Cozumel dive trip, with the first dives of the day down to 100-110'/30m; a single 5 minute stop at 15'/4.5m from > 60'/18m tends to give me a ripping headache afterward; adding a 3~5 minute stop at 40'/12m, a 3~5 min stop at 20'/6m, and then hanging at 10'/3m for as long as possible (first to the safety stop, last on the boat) alleviated the post dive headache/fatigue on the 100'/30m+ dives. its a super conservative ascent profile, but it works for us.

 

[namerg]

Wow lots of comments on this. I have seen a lot the "shallow diving" phrase and also I the book. Can someone describe me with words or a pic, what does "shallow diving" mean ? I understand it like you ascent like if you were stepping on stairs...sorry my English is not my first language. Thanks a lot for your help.

 

[AlexL]

I have seen a lot the "shallow diving" phrase [...]. Can someone describe me with words or a pic, what does "shallow diving" mean ? I understand it like you ascent like if you were stepping on stairs.

'shallow diving' is just that, dives less then 40~60'/15-20m. anything deeper than 60'/20m is 'deep diving'. with shallow diving, you're usually not pushing that much ppn2, and your (no stop) decompression obligation is low enough to be effectively ignored; standard 3-5 minute safety stops at 15~20'/5~6m work just fine for those profiles.

you're thinking of 'staged' ascents; its a way to control your accent rate by going up by X feet/m, waiting for a timer to click over a tick, and then going up another X feet/m; repeat until you're at the safety stop. dive computers with ascent rate readouts have made this practice mostly obsolete in rec diving.

 

[namerg]

Ohhhh okay okay. Now I know the shallow diving concept. Thank you very much AlexL

 

[Lorenzoid]

Relax. All of your fellow students in the class will have the same questions as you do. If you are unsure of something after your instructor explains it, then ask for clarification. The course is designed to be very simple.

 

[namerg]

Ohh ok. Thanks Lorenzoid. It conforts me.

 

[Necklinsberg]

Okay Okay i just want to have an idea...because my course is a two day weekend...and i am totally new with this. I have more questions ....oh well ....

Your entire class -- book work, confined water, open water certification dives is conducted over 1 weekend?
Or am I misunderstanding what you are saying?

 

[namerg]

Nope just in the pool.

 

[rick00001967]

ascend from the SS as slow as you can manage - this is where the biggest volume change occurs.

^^^ i rarely hear others promote this. thx