Recreational Scuba Deco Diving

[tursiops]

After all, diving this way is not new.

No, it is not new, it is quite old. So is diving without an octopus. The recommended best practices today do not concur with some of the old practices.

 

[rx7diver]

No, it is not new, it is quite old. So is diving without an octopus. The recommended best practices today do not concur with some of the old practices.

@tursiops,

I don't use an octopus, either. Why would a solo diver require an octopus? And I don't use a PDC (except sometimes to record my dive). I use published tables.

Honestly, I am not asking about best practices, or agency training standards, or certification levels, or anything else, except what is it that people actually do (regarding RSDD)? Simple question, I would think.

rx7diver

 

[Ouvea]

@tursiops,
Honestly, I am not asking about best practices, or agency training standards, or certification levels, or anything else, except what is it that people actually do? Simple question, I would think.
rx7diver

The training standards has been brought into this thread to support the choices that some divers make. Many members on this this board do not perform these types of dives because they are contrary to the training agencie's best practices recommendation. It benefits our entire on-line community to understand the reasoning behind the choices we make as divers, in the planning and the execution of certain dive profiles.

 

[tursiops]

@tursiops,

I don't use an octopus, either. Why would a solo diver require an octopus? And I don't use a PDC (except sometimes to record my dive). I use published tables.

Honestly, I am not asking about best practices, or agency training standards, or certification levels, or anything else, except what is it that people actually do (regarding RSDD)? Simple question, I would think.

rx7diver

Seriously, it sounds like you are trying to validate that what you do is OK...perhaps because lots of other people do it too.
Maybe then your question should have been: Who else dives the way I do, deco with single tank, tables with no computer, solo, no alternate air source?

 

[Blackcrusader]

I do not find this argument compelling. In the PADI rec courses I took, the instructions for how to use one's computer were simple: do what it says. When you put your GFs to 35/75, you're making an agreement to yourself to follow it. If you are willing to accept a higher risk of DCS, the right way to do it is to set your computer to a more progressive mode. From your chart, GF Lo of 45 yields similar bottom time to DSAT, so that's the obvious choice here. Or use a different computer.

I do not recall PADI course materials in OW or AOW or Rescue covering Gradient factors in the materials however it's been a long time since I did courses. 2015 maybe the last time I did a course. All the new OW and even AOW divers I see doing courses use the dive centers dive computers which are often Suunto DC's and they are not taught to change their settings from high to medium to low. I dive in Asia so talking Thailand Indonesia and Philippines where I dive. You will see OW and AOW divers on their once a year dive vacation without dive computers and they rely on the DM guides for the dive.

 

[jborg]

Having a computer that displays SurfGF gives you an easy way to determine on the fly whether you are still within NDL or not, regardless of how the computer is set up? That is, it may be set to 35/75 (and you might usually follow it), and it may say that you have a deco obligation, but SurfGF is 82%. In this circumstance one might feel justified in saying "nah, I'm actually still OK to surface" regardless. (But then this would not be "RSDD" per this thread.)

 

[rx7diver]

Seriously, it sounds like you are trying to validate that what you do is OK...perhaps because lots of other people do it too.
Maybe then your question should have been: Who else dives the way I do, deco with single tank, tables with no computer, solo, no alternate air source?

@tursiops,

Nowhere in any of my posts in this thread (or anywhere in any SB thread, or anywhere else, I think) have I stated, either directly or indirectly, that I personally engage in deco diving using a single tank. Are you confusing me with someone else? Did you mean to post in a different thread, responding to something else?

rx7diver

 

[Blackcrusader]

Having a computer that displays SurfGF gives you an easy way to determine on the fly whether you are still within NDL or not, regardless of how the computer is set up? That is, it may be set to 35/75 (and you might usually follow it), and it may say that you have a deco obligation, but SurfGF is 82%. In this circumstance one might feel justified in saying "nah, I'm actually still OK to surface" regardless. (But then this would not be "RSDD" per this thread.)

I would think that most DC's have updated firmware to show SurfGF. Shearwater added it after being asked about it. It is just not shown on the main screen by default though.

 

[tursiops]

@tursiops,

Nowhere in any of my posts in this thread (or anywhere in any SB thread, or anywhere else, I think) have I stated, either directly or indirectly, that I personally engage in deco diving using a single tank. Are you confusing me with someone else? Did you mean to post in a different thread, responding to something else?

rx7diver

Sorry, I really don't know what it is you do. I'm guessing, based on your statements.
Is the rest of my guess right?

 

[rx7diver]

Sorry, I really don't know what it is you do. I'm guessing, based on your statements.
Is the rest of my guess right?

No need to guess, @tursiops. Here are my answers to my OP:

1. Seldom, occasionally, or often? Well, I ceased deco diving altogether shortly after 2001 when I began my family. However, at that time I had settled on using air-filled, back-mounted, independent doubles (HP 3,500 psig 120's) for the type of solo deco diving in SW Missouri and NW Arkansas that I was doing and was likely to continue doing.

2. Shore diving, or boat diving? This was shore diving (walk-in diving) in Army Corps of Engineers lakes in SW Missouri and NW Arkansas.

3. Fresh water, or marine? Fresh water.

4. Buddy diving, or solo diving? Solo diving.

5. Rig? (For example: Single cylinder, no pony/backup/bailout? Single w/ pony? Back-mounted independent doubles? Back-mounted isolation-manifolded doubles? Side-mount independent doubles? Something else? What is/are the cylinder capacity/ies?) Air-filled, back-mounted, independent doubles. (So, two complete, independent regs. No long hose. No octopus. No AIR II.) My deco dive schedules were based on the Navy Dive Tables. My usual approach, conservative, was to be back at the planned first deco stop by the time my planned Bottom Time time expired.

6. Exposures you typically plan for (i.e., planned max depth, planned bottom time, and planned deco stops and times)? Well, at that time I was planning for my total deco time to not exceed ~15 minutes, usually.

7. Typical activities? (For example: Simple sightseeing? Photography? Food hunting? Artifact hunting? Scientific/research diving? Something else?) Looking at submerged rocks and submerged tree stomps and freshwater fish, and intending to improve my U/W photography.

rx7diver