A question about half missed safety stop

[luvspoodles]

I have a question that I have wanted answered since Thanksgiving. My husband and I went diving in Cozumel. We were new divers (only about 10 dives under our belt). The ascents and descents are free, with no line. I had been having difficulty with my buoyancy, and I had the divemaster stay close to me and hang onto me during the safety stops. This was difficult for me as I had no line to hang on to. On our 6th dive of the trip, we were doing the Santa Rosa Wall, and we dove to about 85 ft. My husband and I had discussed and decided that he would help me ascend, and help me hold my safety stop at 15 feet. Well, when it was time to go up he grabbed me and started the ascent. I was not comfortable yet diving and so my brain was not working, so I did not dump the air from my bc. On the way up, I kept noticing how fast we were going, yet of course I did nothing. Suddenly I notice that he is pulling on me and now he is pulling at my feet trying to get me down to do the safety stop. I look at my gauge and I am up to 7 feet and then he finds a way to vent the air and I go down to do the stop. I have done about 20 dives since this time, and have learned quite a lot. So yes, I know that I need to vent air before I ascend but I had trouble thinking in those first dives. After we came up, my husband and I argued...I thought he tried to kill me by pulling me up too fast but then I became aware that it was my fault because I had not vented the air. The divemaster was not worried at all and said that I was fine. I went on the next dive to about 50 or 60 feet and I was fine. I was unfortunately not using a computer, as I do now.
My question is this:
-Is going to 85 feet and then coming up to 7 feet without a safety stop extremely dangerous?
-Was it necessary that I went back down to do my safety stop?
-Was it safe that I went on the next dive after a surface interval?
Thank you in advance for your replies. I know that I'm fine and nothing happened but I feel that education on what happened would help me be a more knowledgable diver, which is what I am really striving for.

 

[Curt Bowen]

My question is this:
-Is going to 85 feet and then coming up to 7 feet without a safety stop extremely dangerous?
-Was it necessary that I went back down to do my safety stop?
-Was it safe that I went on the next dive after a surface interval?
Thank you in advance for your replies. I know that I'm fine and nothing happened but I feel that education on what happened would help me be a more knowledgable diver, which is what I am really striving for.

This all depends on how long you were at 85 feet and if it was the first dive of the day.

Without this info, I could not give the correct answer.

 

[luvspoodles]

I wanted to add one more thing to my post. I may have actually gone up to 3 feet or less, and only noticed the gauge at 7 feet. My mind was unclear but I remember looking at the surface and it was sooo close...

 

[luvspoodles]

This all depends on how long you were at 85 feet and if it was the first dive of the day.

Without this info, I could not give the correct answer.

We were at 85 feet for a large portion of the dive. I don't remember for how long because as a new diver I was too busy trying to stay alive. It was the first dive of the day.

 

[Rick Murchison]

-Is going to 85 feet and then coming up to 7 feet without a safety stop extremely dangerous?
-Was it necessary that I went back down to do my safety stop?
-Was it safe that I went on the next dive after a surface interval?

I'm going to make the (large) assumption that your dive profile was within the no-stop limits and that the safety stop you missed was a safety stop and not required decompression stop. In that case the answers are:
No.
No.
Yes.
----
A safety stop is not a required stop - it is to add an additional margin of safety to a profile already within the no-stop limits. To put it in perspective, we dove for decades using tables that were not truncated to the "doppler" limits, made our ascents at 60 vice 30 fpm, and never heard of a "safety stop" - without getting bent.
That's not to say you should treat them casually or to routinely skip them, but rather to say that if you do miss one the sky won't fall.
Rick

 

[tedwhiteva]

We were at 85 feet for a large portion of the dive. I don't remember for how long because as a new diver I was too busy trying to stay alive. It was the first dive of the day.

I would suggest you spend some time working on buoyancy skills in sheltered water - make that the sole purpose of a couple of dives. And do a weight check with about 500 psi in your tank at 15 feet. If you are up AND down at the end of the dive you might be overweighted.

Practice, practice, practice

And enjoy.

 

[Iruka]

Well, assuming you (or the DM) had planned the dive to be a "no decompression" dive, there's not a significant DCI risk in making a direct ascent to the surface. Of course, it's BEST to make a safety stop, but the point of no decompression diving is that there's not a SIGNIFICANT risk in missing it. If you had been deep enough long enough (you'd have to know time & depth for that) to require an actual deco (not safety) stop, then you would have, of course, a greater risk by making that ascent.
You'll find there's not always agreement on certain things, but in general, it's not recommended to get back in the water to recompress if you miss a deco stop. You (probably) just missed a safety stop, rather than a deco stop. Personally, I'd drop back down & complete the stop, but others may disagree. Actually, you only went shallower than you wanted to during the safety stop....something you probably won't do often as your bouyancy control improves. I'd say you made a common, and (if it wasn't a deco dive) not very serious mistake, one that you can learn from & try not to repeat....but don't beat yourself up over it. (there are people here who will be happy to do that, ha ha) One bit of advice, (in addition to developing good buoyancy control) is to try to virtually stop well BEFORE 15'...maybe 20 or 25'....then carefully work your way up to about 15'. That way, you'll have a little margin of error as you're approaching the "deeper" stop, and if you miss that, you should still be under 15'.
As far as the "was it safe to do the next dive?" question, I'm not a doctor, nor have I played one on TV.....but a missed safety stop on a NO DECO dive wouldn't prevent me from doing (or allowing others) to do a subsequent dive. You might extend your surface interval, or make the 2nd dive more conservative than usual....hang out shallower than the rest of the group, do a longer safety stop, whatever. It's pretty much up to you in a case like that, and you can skip the 2nd dive if you feel it's unsafe. Again, all this is assuming it was a no deco dive profile. Oh, one other little thing occurred to me...it would be best not to rely on someone else to help you ascend....you really should try to get comfortable doing this yourself, or try to dive sites with a descent line if you have real problems with buoyancy. Good luck & keep diving!

 

[Dr Deco]

Hello luspoodles:

Missed Safety

As the others commented, a missed safety stop is not really a terrible tragedy. It also would not be the cause for changing your next dive. There is actually a large margin of safety built into decompression tables, that is why meters will give different decompression times for various divers yet all will ascend bends free.

Surface Activity

what is more telling is the amount of stressful activities engaged in during the surface interval - especially right after surfacing. This activity will increase decompression bubble growth during the interdive interval and mitigate the elimination of dissolved nitrogen. This nitrogen is then - unwittingly - added to the next dive. :11:

Dr Deco :doctor:

Readers, please note the next class in Decompression Physiology :1book:
http://wrigley.usc.edu/hyperbaric/advdeco.htm

 

[chrisch]

Good advice I feel.

You might want to investigate the use of a delayed surface marker (DSMB) as an aid to holding your depth for the stop. Your LDS should stock them and show how to use it, if you are still unsure any decent intructor should run through it with you as an inwater exercise for a few dollars.

Chris.

 

[luvspoodles]

Thank you so much for your replies. I am so glad that I asked my question. I have felt like such a fool ever since it happened and I was afraid to bring it up as a question to anyone. I learned so much from your replies. Now I understand why no decompression diving is called that, and why the safety stop is purely a stop for safety. It makes sense. Most of you asked if it was a no decompression dive and I am fairly sure that it was. I did not have a computer at the time, but the divemaster was using the tables and it was a bunch of tourists in the water, lots of us new to diving, and so I'm positive they planned it a no decompression dive. On a positive note, my buoyency is much better now, and I practiced hovering at 15 feet on my next vacation to Grand Cayman, even though we had a line. We are going back to Cozumel in November, and I will use the advice to stop at 20 to 25 feet, and slowly make my way to 15 feet. Thanks!