Recreational Scuba Deco Diving

[Blackcrusader]

Gentle SB Members,

I am interested in knowing (a) if you engage in what I define above as "Recreational Scuba Decompression Diving", and (b) if you do, what are the particulars/details? That's it. Nothing more complicated than this. Thank you to everyone so far who replied, answering my OP. Thanks, rx7diver

OK yes I have done it. I do not plan on doing it. It has occurred when my dive buddy who may well be an instabuddy with CMAS or BSAC or some other agency with deco training decides to exceed NDL to get those oh so needed photos of some critter that are rare to see. These are often instructors and I know some were PADI instructors and I do not know if they had formal deco training.

I've also done it as a planned deco dive with another trained deco diver but not with a dive center. I think unfortunately agencies and some dive centers drill into recreational divers that deco is dangerous and you will die and end up with a plaque on the wall. One of my friends is a PADI instructor. She would always advise students and divers she was leading to start to ascend when they got to 5 mins to NDL. She would see me with 2 min to NDL at 30m depth and say she would prefer I didn't do that. Finally this year she did a sidemount course with deco dives. She was very nervous about going on deep dives and getting narced and also going into deco as her whole padi experience was don't go into deco.

 

[tursiops]

PADI is but one certifying agency. There are some operators who will take BSAC Sports Divers as they are Deco trained divers. Deco dives PADI want to say are tec dive so they can sell their Tec 40 Tec 50 certs. BSAC sports diving is already 50m on air. Do I need a Padi Tec 50 to dive to 50m?

So no PADI recreational dive allows for DECO dives. Switch to BSAC

Your posts are getting tiresome. You say the same thing, over and over, no matter which thread.

 

[Blackcrusader]

Your posts are getting tiresome. You say the same thing, over and over, no matter which thread.

Sorry to have bothered you.

 

[Centrals]

So no PADI recreational dive allows for DECO dives. Switch to BSAC

PADI is the most popular diving agency in Asia if not in the world. They have their own standard and so are the others.
There is NO need for me to switch over to BSAC because I am IANTD Full Trix cert.

As I had already said before I have came across any dive operator that will let me do a deco dive without Tec certification.

 

[tursiops]

If I plan a deco dive, I want some redundant gas, and preferably some higher-percentage O2 gas for accelerating the deco.
If I don't plan a deco dive, I don't do a deco dive.
if I were to plan an NDL dive, and for some reason when into deco (that has never happened), I'd get the hell out of there and up to a first (and hopefully only) stop, and deco out on "backgas," no matter whether it was on my back or my side(s).

My original training was pre-PADI, my first cert card was NAUI, my tech credentials (through CCR and Adv Trimix and Full Cave with stages) are TDI and NACD and NSS-CDS, and I'm a PADI and (lapsed) SDI/TDI instructor. I don't think all the agency differences are the point; the point is that if you are planning to dive with a ceiling -- hard or soft -- then you ought to plan for that kind of dive, and not cut corners. That lesson has been learned the hard way -- through deaths of people who thought they were better than the training and rules and recommendations. RIP.

I take no issue with the BSAC training, but in my personal experience beyond 40m on air is too narced for me. 57m on air (two tanks on my back plus a slung deco cylinder) was my max; I will never do that again. MUCH too deep for me. And that was in warm, clear, no-current water. If anything had gone wrong, I probably would not be writing this post.

 

[rjack321]

Well does that include 21% air it's also a gas after all. Would you do a nitrox 26% mix and do a deco dive at 30m then ascend to a point where your deco obligation is cleared on Nitrox 32% pony? Or even 21% to 30m and clear deco obligation on 32% on say a 10l pony.

I believe rx7diver might ask would you do a 30m dive on air and do say 10 minutes of deco and then clear deco obligation using a single tank for the dive? Your dive buddy doing the same. Or you could use Nitrox 32% to give longer time to get to deco then need enough to complete the dive on a single tank?. Most recreational diving is done at 30m or less but of course we should account to 40m.

None of the above.

I don't go into deco on a single tank
I don't dive air
I don't dive with ponies
32% is completely useless as an accelerated deco gas and you can't breath it at 40m so its not redundant gas either.

On a single tank I dive 32% at <30m and end up with 50 to 75min dives.

If I want to deco dive (and/or >30m) I plan it as a deco dive with redundant doubles or sidemount tanks and a proper deco gas like 50% or O2.

 

[rjack321]

@jack321,

I actually considered using that term ("backgas deco"), but determined it wasn't sufficiently flexible to let side-mount diving be included as a possible kit option here.

rx7diver

sidemount tanks are still typically called "backgas" or "bottom gas" to distinguish it from deco gas

 

[dewdropsonrosa]

I was on the edge of RSDD-type dives in the last few months before I started technical dive training. There's a particular wreck in the area where the top deck sits around 130' (40m) and the sand is at 150' (45m). Recreational divers can enjoy short dips to explore the deck and the masts.

I was among a handful of upper-level recreational divers who would bring an AL80 or HP100 as back gas and sling an AL40 for redundancy. Breathing gas was air or EAN26/EAN28.

Bottom times were usually 7-8 minutes. If we jumped in first -- which is easy to do in rec gear -- we could do our first dive, have an hour SI, and finish the second dive around the same time that the tech teams surfaced from 20-30 minutes of BT and deco.

We weren't striving to incur deco obligations, but sometimes we would run 60-90 seconds behind schedule to get back to the mooring line. Our computers would accrue some deco during this time. I think at the very worst, my computer assessed a 2-minute stop at 20 feet. With a gentle but consistent ascent rate of 30fpm, everybody's computer would clear the deco on the way up.

I now have the appropriate technical training and equipment. I wouldn't do this anymore and I wouldn't encourage other people to do it, either.

 

[rjack321]

Bottom times were usually 7-8 minutes. If we jumped in first -- which is easy to do in rec gear -- we could do our first dive, have an hour SI, and finish the second dive around the same time that the tech teams surfaced from 20-30 minutes of BT and deco.

Seems hardly worth the charter cost, or even wrestling on a drysuit for 2x 8mins of bottom time. Was this a 3 dive charter so you could at least get a decent amount of time in on a shallower site for the cost? I hope.

(even 20mins @ 140ft is still under an hour total and I would expect those divers wanted a 2nd dive someplace else too)

 

[Edward3c]

PADI is but one certifying agency. There are some operators who will take BSAC Sports Divers as they are Deco trained divers. Deco dives PADI want to say are tec dive so they can sell their Tec 40 Tec 50 certs. BSAC sports diving is already 50m on air. Do I need a Padi Tec 50 to dive to 50m?

So no PADI recreational dive allows for DECO dives. Switch to BSAC

Sorry but you’re well out of date on BSAC standards.

Sports Diver is limited to 20m on qualification, depth progression dives to 25, 30 then 35m with an instructor extend the depths to 35m. To be certified to 50m you need to be Dive Leader qualified, and do the depth progression dives to 40, 45 then 50m.

In September, BSAC issued guidance that dives beyond 40m should be done using Trimix, see here.