"Riding your Computer Up" vs. "Lite Deco"

[lowviz]

...//... So, this "lite deco" of which you speak. Do you carry enough redundant gas to meet any deco obligation you anticipate incurring? ...

Yes, I believe in something I was told long ago: "Always have something to breathe."

For light deco, I only need to know how long is too long. I know at a glance, see pic. The last number on each line is what I would surface with. I can chip into that number for more down time and 500 on the surface, but that tiny buffer disappears stupidly fast at depth...

obviously not in the normal division of recreational diver anymore, but here is my personal definition of "light deco" ...

Awesome post.

 

[stuartv]

Before I started tech training, I was only diving with my Oceanic Atom recreational computer. I never took it into deco.

Now that I've done tech training, I consider "light deco" to be deco done on back gas that is approximately the same ascent I would do anyway, even if I didn't exceed the NDL. I.e. no more than a 5 to MAYBE 10 minute hang at 15'.

In practice, I now do all my dives with at least one tech computer. On recreational charter boats, one tech computer plus my Atom. So, I'll set my tech computer to Gradient Factors I normally use and then dive right up to the NDL on my recreational computer. The NDL on a DSAT computer (e.g. my Atom) is almost always into deco on my tech computer. So, I'll stay down to the NDL but then do my ascent per whatever my tech computer prescribes.

If deco is going to be any much more than, essentially, a continuous ascent with a 5-ish minute stop at 15 or 20 feet, then I'll do a formal dive plan like any other proper tech dive.

A direct ascent from 130', with a 5 minute safety stop is only a 9 minute total ascent and just doesn't require THAT much gas*. If you're aiming to be at the surface with 500 psi, you can err by a pretty decent margin and still get out without skipping any deco (though maybe going well below 500 psi in the process). Of course, if you stay down that long, build up a 5 minute deco obligation, and your buddy goes OOA right as you hit 1000 psi and you are starting up, well.... then you will learn the hard way why you should have redundant gas.

*If you are stressed and chugging 1 cu-ft/min, it's < 20 cu-ft - i.e. roughly 700 psi from an AL80. If you start up with 1000psi, you should be able to make it even while stressed and easily if breathing normally. And if you're at 130' and breathing your tank down past 1000 before you start up, well, you are not being very smart, regardless.

 

[dumpsterDiver]

lite deco to me is deco I probably (I hope anyway) that i could blow off (skip) without getting hurt. I consider lite deco for mayself to be 5 maybe 7 minutes.. more than that.. I just take it a little more serious.

For example, I could probably clear "lite deco" with a 13 cu-ft pony bottle. It is obviously a subjective term with no definition that everyone will agree with.

 

[lowviz]

...//... It is obviously a subjective term with no definition that everyone will agree with.

Exactly, I'm just fishing for rough numbers and fuzzy reasoning.

-Just for my own curiosity as to where I stand with respect to other opinions.

Thanks.

 

[lowviz]

In response to post #10 of this thread, I see that @Scuba J7 often "likes" posts that cast me in a negative light.

Your extensive profile says that you are a Scuba Industry Professional who has been certified for three years. Any chance that you are with ScubaPro? If so, that would be great! Most of my stuff is SP!

This could be the very first time that I was "contacted" (sort of directly) by ScubaPro! I came close here: Welcome to the SCUBAPRO forum!.

Oh wait, SP deleted that thread and with it, my substantiation. No problem. Deep down, I know you care...

EDIT: It's back!
XPL Jetfins
So you guys really DO exist...

 

[redacted]

I am quite satisfied as an OW diver staying within Ndl limits.

 

[Scuba J7]

Don't flatter yourself, I simply got a laugh out of the picture posted

I don't work for Scubapro although the shot I use for my avatar has been considered for marketing by SP, I do work for a SP dealer which is why you'll see me pretty much only in SP gear(can't beat key man prices)

I wasn't liking post just because they cast you in negative light, although there have been some post I liked for the snark provided, I would have to see each individual post to know why I liked them.

In response to post #10 of this thread, I see that @Scuba J7 often "likes" posts that cast me in a negative light.

Your extensive profile says that you are a Scuba Industry Professional who has been certified for three years. Any chance that you are with ScubaPro? If so, that would be great! Most of my stuff is SP!

This could be the very first time that I was "contacted" (sort of directly) by ScubaPro! I came close here: Welcome to the SCUBAPRO forum!.

Oh wait, SP deleted that thread and with it, my substantiation. No problem. Deep down, I know you care...

EDIT: It's back!
XPL Jetfins
So you guys really DO exist...

 

[Ouvea]

I believe we need to look a fundamental difference in the dive profile. Does the diver plan on exceeding the NDL and incur a specific amount of deco. As such, does the diver account for the gas required and what happens when SHTF. If it's a planned deco dive, I don't see any problems. Although, you should obtain the necessary training. While the internet has loads of information, you may have overlooked something. There is no substitute for training and actual experience. On the other hand, we may have a scenario where the diver unwillingly enters deco. IMHO, scenario one is okay. Scenario two is just asking for trouble.

obviously not in the normal division of recreational diver anymore, but here is my personal definition of "light deco"

light deco for me is a deco obligation where the risks/rewards of doing staged/accelerated decompression is not worth it. Ty, and less riskpically that is in the vicinity of 15 mins and corresponds to whether or not I feel the need to dive doubles/sidemount.

Most of the time for me, going to 50/50, 80/20, 100% whatever O2 and carrying the extra bottle is not worth saving 10 minutes of decompression. Depending on conditions, that may go up or down. In caves, I will almost always take an O2 bottle with me if planned depth is deeper than 60ft or so. It is pretty inconsequential to bring a 30 or 40, and even if I'm only doing a 3 minute safety stop, doing it on O2 doesn't hurt. Bottle is staged, dropped off quickly, and the surface conditions are easy.

In OW, I'll avoid that extra bottle as long as possible because I have to carry it with me, so I'll do planned deco on backgas up to a point, and that point will move depending on the dive profile and conditions. Cold, blue water, rough seas, etc. decompression? I'll probably bring that bottle after about 8 minutes of planned deco on backgas. I'll be doing at least 3-5 minutes to stabilize everything anyway if it was an NDL, so grabbing a small O2 bottle is worth it to get out of there quickly. Warm water with a reef or something interesting to look at? I'll stay on backgas because it gives more depth flexibility if there are pretty things to look at, less logistics concerns.

 

[lowviz]

Don't flatter yourself, I simply got a laugh out of the picture posted

I never flatter myself. I see that as a major flaw in an individual. So, you claim to be a "Dive Industry Professional". What is that, exactly?

That pic was just Andy being Andy. Made me laugh too, that jerk. I read the text in front of the pic, good stuff in there.

...//... I don't work for Scubapro ...

Sure sounded like it from your "Information" and avatar...

...//... although the shot I use for my avatar has been considered for marketing by SP ...

It flatters you, go with it.

...//... I do work for a SP dealer ...

Ambiguous.

"I do work as an employee for a SP dealer"
or is it
"I also do work for a SP dealer"

...//... there have been some post I liked for the snark provided...

That says a lot.

 

[lowviz]

I am quite satisfied as an OW diver staying within Ndl limits.

You and I aren't all that different. Read what Andy has to say:

...//... I've encountered this occasionally, where 'recreational divers' are pushing bottom times on dives in the 130-145ft (40-45m) range. I'll whisk past them on a 10m /min ascent rate en-route to formal stops, only to see them overtake me in the shallow phase and exit the water sooner.

Based on comparable total ascent (deco) times... they've forgone effective decompression at beneficial gradients purely to sustain the 'illusion' of maintaining a 'recreational' profile without formal stops. ...

If you (not YOU awap, but the grand YOU) strive to stay away from your NDL, then all is well. If "you" are one of those seeking a more liberal algorithm/PDC to get every last minute of bottomtime, then you are just looking for ways to fool yourself into thinking that someone drew the "safety line" here or there and you want your toes over it to get full value from your dive.