Safety Stop Necessary?

[cnctina]

Hi,

I just made a dive and went to a depth of 86 feet. We did do a safety stop although I used my friends computer as I do not have one. I know it was stupid and will never do it again. In fact, we weren't even planning to go that deep.

Anyways, we did do a safety stop. I haven't dived in a month or so, so I was having trouble with my buoyancy. Anyways, at one point at got within five feet of the surface but then dropped back down. Anyways, should I be okay regarded decrompression sickness?

Thank you.

Is your friend whose computer you were using still alive?

 

[serambin]

That link provided fascinating reading. From what I gather from it, a relatively fast ascent to half the total depth, and then a five minute stop...then on to 15 feet and a normal stop is what DAN's research recommends?

Safe Diving

Jeff

Looking at the results, the best case was a 5 min stop at 45 feet and a 5 min stop at 20 feet. The drop in bubbles found by Doppler was reduced by 66% over the conventional stop (at 15 - 20 feet) extended to 5 min, with the same ascent rate in both cases of 33 feet/min.

Very impressive.

Stan

 

[getwet2]

So I should be okay right? I haven't really felt any major symptoms. I felt a little pain in my arm twice but nothing unbearable.

Thanks guys.

This could be one of two things, based on this post and the earlier post it's either a very inexperienced diver or a TROLL!

 

[serambin]

This could be one of two things, based on this post and the earlier post it's either a very inexperienced diver or a TROLL!

You mean one of those ugly little dolls with the funny hair? Nah, I know one of those when I see it.

Stan

 

[Shannon M.]

Kind of outside the scope of the original question, but since it was talked about, here is part of an article I was recently working on;

Most of you have probably been taught to make a 3-minute stop at 15 feet during recreational scuba diving. In fact, most national training agencies teach you to do just that. There is a school of thought that teaches another way to do it. This technique is in line with Bruce Wienke's RGBM (Reduced Gradient Bubble Model) which is accepted and promoted by NAUI and others. On the recreational side, it's called the rule of halves, that is to stop half way up the water column, make a safety stop for one to two minutes and then stop again at 15 feet and complete another safety stop for two minutes. Why? The RGMB theory supports that when diving deeper than 20-30 feet, stopping half way up the water column reduces the sub clinical micro bubbles (silent bubbles or seeds) that can turn into clinic bubbles, which cause Decompression Sickness (DCS). So if you were making an 80-foot dive, you would stop at 40 feet for two minutes, and then stop at 15 feet for another two minutes. A related theory suggests that when only making a 15-foot safety stop, you are actually treating your self for sub clinical decompression sickness. The theory goes on to say that over enough time, enough sub clinical decompression sickness can wear on your body and cause problems later, that you may not necessarily relate to diving. This is only theory but makes sense to me as a diver. The traditional 15 foot/3 minute stop is based on the dissolved gas theory that Haldane developed decades ago and the U.S. Navy and a lot of other agencies adopted. The RGBM model is newer and strives to get rid of as many micro bubbles or silent bubbles as possible by letting them come out via natural respiration at deeper depths (deep stops). Another thing that it does for you is naturally slows your ascent because you have to stop two times instead of one near the surface.
Whatever technique you decide to use, do so purposefully and continue your education so you can learn the stuff you don't know.

ref:Bert Wilcher/DAN/NAUI Pubs

 

[djanni]

We dove with a DM recently who said his age was 58. He also claimed 1200 dives a year and had been diving at that rate for over 10 years.

He attributed his longivety (outside his being physically fit) to two things:

1. Nitrox - He said he uses Nitrox religiously and as often and as the dive plan will allow and he likes to increase the % as the day goes by. He'll start with 32% and finishes with 36%. He would say... every day, every day, every day.

2. Length of his safety stop. He specifically said he likes to stop at 1/2 the dive depth (if it's more than about 90') for 2 minutes and then again at 18' (18' is marked off on his lift bouy line) for a full 5 minutes. He would say... every dive, every dive, every dive.

He would laugh out loud and say "every since I started doing those things I'm like that pink bunny rabbit... I can just keep going and going."

Those long stops may not be necessary but he swares by them. The Nitgrox too but I can relate to that a bit.

Anyway, food for thought.

 

[Tollie]

1,200 dives a year? Thats more than 3 per day every day of the year.

 

[ScubaSixString]

Kind of outside the scope of the original question, but since it was talked about, here is part of an article I was recently working on;

Most of you have probably been taught to make a 3-minute stop at 15 feet during recreational scuba diving. In fact, most national training agencies teach you to do just that. There is a school of thought that teaches another way to do it. This technique is in line with Bruce Wienke's RGBM (Reduced Gradient Bubble Model) which is accepted and promoted by NAUI and others. On the recreational side, it's called the rule of halves, that is to stop half way up the water column, make a safety stop for one to two minutes and then stop again at 15 feet and complete another safety stop for two minutes. Why? The RGMB theory supports that when diving deeper than 20-30 feet, stopping half way up the water column reduces the sub clinical micro bubbles (silent bubbles or seeds) that can turn into clinic bubbles, which cause Decompression Sickness (DCS). So if you were making an 80-foot dive, you would stop at 40 feet for two minutes, and then stop at 15 feet for another two minutes. A related theory suggests that when only making a 15-foot safety stop, you are actually treating your self for sub clinical decompression sickness. The theory goes on to say that over enough time, enough sub clinical decompression sickness can wear on your body and cause problems later, that you may not necessarily relate to diving. This is only theory but makes sense to me as a diver. The traditional 15 foot/3 minute stop is based on the dissolved gas theory that Haldane developed decades ago and the U.S. Navy and a lot of other agencies adopted. The RGBM model is newer and strives to get rid of as many micro bubbles or silent bubbles as possible by letting them come out via natural respiration at deeper depths (deep stops). Another thing that it does for you is naturally slows your ascent because you have to stop two times instead of one near the surface.
Whatever technique you decide to use, do so purposefully and continue your education so you can learn the stuff you don't know.

ref:Bert Wilcher/DAN/NAUI Pubs

A bit mathy but Pyle's technique

1) Calculate a decompression profile for the dive you wish to do, using whatever software you normally use.

2) Take the distance between the bottom portion of the dive (at the time you begin your ascent) and the first "required" decompression stop, and find the midpoint. You can use the ambient pressure midpoint if you want, but for most dives in the "technical" diving range, the linear distance midpoint will be close enough and is easier to calculate. This depth will be your first deep safety stop, and the stop should be about 2-3 minutes in duration.

3) Re-calculate the decompression profile by including the deep safety stop in the profile (most software will allow for multi-level profile calculations).

4) If the distance between your first deep safety stop and your first "required" stop is greater than 30 feet, then add a second deep safety stop at the midpoint between the first deep safety stop and the first required stop.

5) Repeat as necessary until there is less than 30 feet between your last deep safety stop and the first required safety stop.

Works with rec dives too. Replace Decompression Stop with Safety Stop


http://www.bishopmuseum.org/research/treks/palautz97/deepstops.html

 

[Wayward Son]

I think you're gonna live.

 

[djanni]

He said he averaged 4 dives a day, 6 days a week and 50 weeks a year. I thought that was a lot myself. Cut it to 3 dives a day on average and it's still 900. I would have more than impressed with that number.

1,200 dives a year? Thats more than 3 per day every day of the year.