Do not ever say you are a rescue diver

[BlueTrin]

That's just a GUE term that no one else uses outside of the DIR world.
There are some interesting historical threads on this concept:

Reasons to do "Minimum Deco"

"Minimum Deco" is the most common name given for a practice of making a very slow (10ft or 3m per minute) ascent from approximately one half of your average depth on dives that most people would call "No Deco" dives. Another name you'll see is "One Minute Ascents" (which I find incredibly...

scubaboard.com

15' Safety Stop vs Minimum Deco

~Thanks to Aaron for the question~ Question: Which is better: a 15' safety stop or Minimum Deco of 1 minute at 30', 20', 10' for recreation NDL dives? Please give your reasoning and/or supporting evidence. Remember the forum is Basic Scuba Discussions.

scubaboard.com

In that thread there is a post from 2010 seems very relevant to this thread 12 years later

I'm not sure this is appropriate to "Basic" scuba discussions, but in the "basic" world of recreational diving, I think the benefits would be so minor as to be statistically unmeasurable. The OP talks of "anecdotal evidence" about improving safety but I hear of no such anecdotes in the enviroment in which I work - which has hundreds of thousands of divers every year. There's a similar post in the advanced forum about the benfits of decompressing uses hyperoxic mixes at different points during ascent.

There's plenty of research available about the benefits of ascent rate versus depth and dive time etc and in some cases, slow ascents seem to marginally increase nitrogen loading in the body, whereas a good old safety stop at 5 metres so dramatically reduces the nitrogen load that ascent rate (within a given timeframe) is almost meaningless. Safety Stops are not a PADI invention, it's well proven theory taught by pretty much everybody.

The argument that all dives are deco dives is of course literally correct, but recreational diving has been developed so that a direct ascent to the surface is possible at all times with minimal risk of the bends. Some argue that the safety stop is a decompression stop, and yes, of course it is, but it's not as mandatory (according to the data) as it is in the realms of Tec diving, safety stop versus deco stop is a matter of semantics, but I think we have well established difference between recreational diving where you make a safety stop and full on decompression diving.

As I said in the hyperoxic washout thread in the advanced forum - for recreational diving it would simply be impossible to teach. For those who are interested in diving on trimix and full tec diving, there are plenty of courses available.

My 2 cents

C.

Reasons to do "Minimum Deco"

"Minimum Deco" is the most common name given for a practice of making a very slow (10ft or 3m per minute) ascent from approximately one half of your average depth on dives that most people would call "No Deco" dives. Another name you'll see is "One Minute Ascents" (which I find incredibly...

scubaboard.com

 

[boulderjohn]

I thinik if you talk with a geologist, an “active volcano” is one with seismic activity under it, and sometimes steam vents on the volcano. Magma is moving under it, which means that sometime in the future it could erupt. We have a number of active volcanos in the Pacific Northwest, including Mt. Hood near me and Mt. Rainier near Seattle. These are volcanos that geologists worry about.

SeaRat

I know this.

That is what a geologist means by calling it an active volcano. For someone who is not a geologist, the word "active" as part of the phrase "active volcano" is confusing, because the more common use of the word suggests that there is some level of eruption going on at all times. That misunderstanding would be understandable to someone in the lay public, but it would be shocking if a trained geologist would not understand that and challenge the use the the phrase "active volcano" to refer to volcanos that are not currently erupting.

I wrote that in comparison to a scuba diving situation.

Scuba Divers use the phrase "decompression dive" to refer to a dive with required decompression stops. For someone who is not a scuba diver, the word "decompression" as part of the phrase "decompression dive" is confusing, because the more common use of the word suggests that there is some level of decompression going on at all times.. That misunderstanding would be understandable to someone in the lay public, but it would be shocking if a trained scuba diver would not understand that and challenge the use of the phrase "decompression dive" to refer only to dives with required decompression stops.

 

[boulderjohn]

In that thread there is a post from 2010 seems very relevant to this thread 12 years later

Reasons to do "Minimum Deco"

"Minimum Deco" is the most common name given for a practice of making a very slow (10ft or 3m per minute) ascent from approximately one half of your average depth on dives that most people would call "No Deco" dives. Another name you'll see is "One Minute Ascents" (which I find incredibly...

scubaboard.com

When I was a UTD diver long ago, I did many a minimum deco dive. I was never told why I should do this.

Several years ago, I set out to write an article comparing different ascent profiles and identifying the reasoning and research supporting each. I contacted GUE headquarters, and I was referred to someone who wrote an extensive explanation about it. I have the emails from our exchange in case anyone wants more than the following summary.

• The primary rationale for minimum deco is the belief that the shallowest part of the ascent should be slower than the deepest part of the ascent.
• The transition point of half the maximum depth has nothing to do with a belief in deep stops. It is because pretty much any diver has the mental capacity to calculate a half.
• The primary reason to use a series of one minute stops from the halfway point to the surface as a means of slowing the ascent is done to be consistent with the way ascents are done in decompression dives. In a sense, it is to maintain standard practice between the two. You might call it practice.
• There is no research whatsoever as to how this ascent profile compares with any other ascent profile in terms of safety.

Several years ago, when I was just starting this study, I made a post in a thread that got me into deep trouble. A couple people in the thread praised the minimum deco approach and said it was great to have learned all that theory. Mystified, I asked what that theory was. Where did the minimum deco approach come from? Why was it superior to a safety stop? It was a genuine question. A number of people answered the question, and I don't believe any two said the same thing. There were references to Buhlmann GFs, etc. There were no references to research. When I finally got the official answer from GUE headquarters, it turned out none of the people who answered were correct.

 

[SlugLife]

This thread has gone so far off the deep-end in so many different ways, that I'm pretty sure it's unsafe to dive this thread without the following Technical Diving certifications:

• Advanced Deep Diving - How to safely decompress after a thread went too deep.
• Semantic Entanglement - How to appropriate deal with and escape entanglement hazards at depth.
• Penetration Diving - How to penetrate rabbit holes deep underwater. Includes rule of third; reserving 2/3rds of your energy for the return trip, and laying line towards the exit.
• Rescue Thread Diver - Never endanger yourself to rescue another thread-diver.
• Hazardous Thread Life - Dangerous marine life that may sting, entrap, attack, or lure you if you venture into their territory.
• Redundant Thread Diving - For your own safety, when your first, second, and 3rd attempts all fail.

 

[BlueTrin]

This thread has gone so far off the deep-end in so many different ways, that I'm pretty sure it's unsafe to dive this thread without the following Technical Diving certifications:

• Advanced Deep Diving - How to safely decompress after a thread went too deep.
• Semantic Entanglement - How to appropriate deal with and escape entanglement hazards at depth.
• Penetration Diving - How to penetrate rabbit holes deep underwater. Includes rule of third; reserving 2/3rds of your energy for the return trip, and laying line towards the exit.
• Rescue Thread Diver - Never endanger yourself to rescue another thread-diver.
• Hazardous Thread Life - Dangerous marine life that may sting, entrap, attack, or lure you if you venture into their territory.
• Redundant Thread Diving - For your own safety, when your first, second, and 3rd attempts all fail.

I recommend the Thread Fudamentals class over these specialties

 

[NorCalDM]

I recommend the Thread Fudamentals class over these specialties

Make sure you are wearing a BP/W with long hose as it is the only way you can trim out correctly while responding from your chair. Also jet fins are the only way you can efficiently maneuver through this thread.

 

[quick_dry]

I recommend the Thread Fudamentals class over these specialties

typical diving - something looks interesting and not challenging at all but then look into it further and find out they're insisting you need a multitude of different overlapping courses or some other agency will do 'something similar but not quite the same' in less courses but with different gear and priced so you can't tell which option makes sense. (Fortunately I have enough computers to browse this with a backup - though no doubt some will insist I'm better off with a new monitor.... and with all these computers on the desk - what is the best routing solution for all these cables?)

 

[Bowcaps]

Whilst the credit of being a RD is one thing, the actual knowledge and ability far outweigh the credit or certification IMHO.

Many years ago, I was in a workshop when a tool broke and went through the hand of the person operating the machine. I looked around, and everyone just looked at the scene unfolding and did nothing. I raced over to a locker marked first aid, grabbed some bandages and attempted to reduce the blood flow from the young engineer's hand. Somebody rang for the base first aiders, and there was an estimated time of 15 minutes. I scooped the young lad up and carried him the 100 yds to the medical station, where he received treatment. In the subsequent investigation, I was criticised as my qualification ran out two months earlier. The medical staff, however, said that quick thinking prevented complications and serious blood loss.

My point is sometimes a bit of paper does not replace the ability to help someone if you have the knowledge to do so.

 

[Wibble]

In the subsequent investigation, I was criticised as my qualification ran out two months earlier.

Must control fist of death….

 

[Subcooled]

There has been a lot of threads about how a diver should introduce herself or himself to a new DS. I have a DM C- Card but I never claim I am a DM as I have never worked as such. I always say I am a Rescue Diver. 90% of the time, I dive with my wife as a buddy. I jump first, tell her I am ok and watch her jumping. I am more experienced than her and I want to be there if she has a problem (overweighted, valve problem,…).
Last week, diving in the Philippines, the DS decided that we would be three in a group. Two groups of 2 including the guide or DM and our group at the back. To make a long story short, the third « buddy » jumped without inflating his BCD and was probably overweighted. He immediately sunk.

Great! One cannot be a diver without sinking!

He was AOW, and should have been able to correct that rapidly but he was not. I saw it, went down in a rush but I could not equalize fast enough so had to slow down.
Eventually, the diver managed to to inflate his BCD and get back to the surface.

Nice.

A bit too fast though so we aborted the dive.

Why?
During those few seconds under water (s)he had not accumulated ANY dissolved nitrogen.
This means that ANY ascent rate would have been perfectly OK, as long as (s)he exhaled.

Then, one Dive Director blamed me for not helping him and said I thought you were a rescue diver. I think he will never say that again after the sh*** I gave him but the point is:
1- If it was my wife, I would have risked rupturing my inner ear. I won’t do it for an insta-buddy.
2- I was a customer and not a guardian. Of course, you care for your buddy (even in a 3 guys team) but there are limits.
3- I should never have said that I am a rescue diver. Those folks believe that I would help them protecting their customers. From now on, I am just AOW with a 40 meters clearance.

You had no duty of care, legally. And you had equalization problems.

The DM obviously expected you to perform. To help in a rescue. I would have done the same, with that knowledge. Even if you were an AOW or an OW. In a rescue situation you MUST help. Laws do vary, but as a diver, some things are expected from you. You do your best to help a fellow diver at risk.

Now, you did have a valid reson for not descending. You can only do what you can do.