Blow a Safety Stop? Redescend ?

[divingguru]

Like many others have said, there are usually not required, only recommended. I wouldn't be too concerned, unless it had been a particularly deep or long dive. I would just keep hydrated and maybe have a little bit longer surface interval. Never go back in or go down to do a saftey stop, no point whatsoever and could be potentially dangerous.

 

[HisLovelyBride]

It is important to note the difference between a decompression and safety stop. Safety stops are a precaution, a good practice, but not required. My computer doesn't lock me out for missing a safety stop, but if I were to miss a deco stop, well, the day would be done with the computer.

Me and my buddy always practice slow ascents and 3 minute safety stops and it is second nature to us now. Thankfully, we have not had a need for an emergency ascent and haven't had to deal with the issues from that.

 

[Blackwood]

because it's a model ... it can only approximate, not describe exactly, what is going on

on a given day, under a given set of circumstances, you can follow that model and get bent

it's all misnomers when it comes to this stuff ... just pick which terms you feel most comfortable with

Oh, yes of course it's just a model. But within the confines of the model, one term is apt, the other isn't.

I'll run with no-stop.

 

[H2Andy]

i think non-stop is more accurate too

i just like to say NDL (confuse the wife)

but honestly, i still haven't wrapped my mind around "non-stop" as being all that different from tables based on NDL's

 

[The Chairman]

It is important to note the difference between a decompression and safety stop.

The safety stop is merely a subset of all decompression stops. There is a difference between mandatory (obligatory) and safety (precautionary) stops, but decompression occurs with ALL of these stops and continues while you are on the surface. Contending that a safety stop is not a decompression stop flies in the face of diving physiology as we understand it. I have seen too many people blow off their safety stop because the boat required them to board with 500 PSI. They weren't going to breathe down that tank any further and risk possibly getting into trouble by the captain. Kinda sad and funny at the same time.

Using the model that all stops are decompression helps us to accept that re-descending is in actuality re-compression or IWR.

Before ScubaBoard, I have to admit that I only did safety pauses. I had bought the download cable for my Suunto Cobra and actually examined my dives. It was embarrassing! I changed my way of diving because of this, adding in a three minute safety stop. Then, a few years ago, NAUI introduced deep stops for OW divers as a matter of policy. I was already doing them, but they seemed more than optional. Also, the fine print finally hit me and I increased my shallow stop to a full five minutes long. Then, early last year I got to hear a talk at the History of Diving Museum down in Key Largo by DAN.

He pointed out that they could tell what type of diver you were by how you were bent. If you had Type I DCS, then you were 95% chance a commercial or tech diver. If you had Type II DCS, then 95% of the time you were a recreational diver. Wow. Of course, he also pointed out that getting bent amounted to little more than statistical noise, so don't get the impression that you WILL get bent! That's when I saw the light. Now I do a full three minute stop at half my depth (if I exceed 80 fsw) and then another five minutes at my shallow stop. I allow ascent rates up to 60fpm below 60fsw, 30fpm up to 15fsw and then 10fpm after that. I also dive NitrOx almost exclusively (yes, even in pools while teaching) for my recreational diving. I have missed only two shallow stops that I can recall in the last five years. One was for two circling bull sharks and the other was for TONS of Jelly fish and a lost anchor line.

I will have to admit that since I started doing deep stops and the full five minute shallow stops, that I have not had any more episodes of extreme fatigue (sub-clinical DCS) after a dive. It's been rather nice to not feel hammered after a dive. This is probably why I am so loathe to giving up a shallow stop, but I can understand Lynne's lucid logic about inadvertently recirculating bubbles by doing so. Thanks to everyone who participated in this discussion. It might have been a little "deep" at times for a few of us, but that's OK.

As it is, I am in the middle of a Advanced NitrOx/Deco procedures class and stops have become more precise and challenging. I started a thread about that over in the advanced section. Feel free to come and join us: http://www.scubaboard.com/forums/te...e-boys-how-precise-should-you-hold-depth.html

 

[DennisW]

Over the years, with experience and education, I too have changed the way I ascend and perform deeper stops as well as my normal safety stop closer to the surface. Makes a lot of sense and the older you get, the more cautious you tend to become. Well, I do.

 

[Granny Scuba]

The word Venous has been used several times in this thread.

I have Venous insuffiency in my left leg. My left calve is considerably larger than my right.
The blood in left leg does not flow back up to my heart properly because of faulty valves.

This was just diagonosed this past Spring, and before I went thru my certification I asked the vascular surgeon if this would conflict with Scuba. The Vascular surgeon said no problem. But I dont think he was a scuba certified VS.

Given all this talk about venous, bubbles, ....etc. I am beginning to wonder if it is okay to scuba with Venous Insuffiency.

 

[Blackwood]

He pointed out that they could tell what type of diver you were by how you were bent. If you had Type I DCS, then you were 95% chance a commercial or tech diver. If you had Type II DCS, then 95% of the time you were a recreational diver. Wow.

Wow indeed. It's almost paradoxical, but in actuality it makes perfect sense from the standpoint of how different groups of divers go about ascending.

 

[TSandM]

Venous insufficiency in the legs will result in slower return of blood from the leg to the heart. This means that bubbles that form in the venous blood are slower to leave the leg. If you formed a LOT of bubbles, you might be at higher risk for type I DCS involving your leg. The bottom line is to follow the kind of ascent procedures that NetDoc describes, and control bubble formation.