What would you do?

[Namreg 58]

Nowhere in there is he asking advise as to what he should do, he wants to know what someone else would do. So I told him. I didn’t say he should, nor did I say he should get training; why? Because he didn’t ask for advise; he was taking a poll.

A rudimentary understanding of deco theory and a set of navy air dive tables is all that is needed to plan and execute the dives the OP is describing. Or as Akimbo posted "It isn't rocket science, study up a little, and have fun".

After Dark, I agree with you on this as when I started diving, all we had was Navy tables to go by and Fenzys were a recent novelty to diving. The gist of my comment was to make you aware that you would upset a few zealots on here by admitting to doing the dive "without the proper training and equipment".

I was merely having a cheap shot at the purveyors of BS on SB along with the nutter converts who in another time and place would have been perfect fodder for Waco and Jonestown given their textbook regurgitations of " if you don't do it.............you're GONNA DIE!"

It's pure insanity to stick your head under water in the first place and anything that transpires after that is called evolution. Diving zealots will have you in a constant state of training to prevent the sky from falling on you and have you looking like a cluster f$%k with redundant this, that and the other waiting for that day to come........which is fine if you don't have a life or friends to distract you.
I liken this kind of diving to driving a car whilst towing a deployed parachute just in case the brakes fail, both of which do wonders for your air and fuel consumption.

The OPs post had a familiar (to me) ring to it so I checked his credentials and discovered that he had extensive tropical diving experience in various locations and would know that conventional rules of narcosis and sac don't apply when diving in warm tropical water. I figured that he was posing a rhetorical question in order to get some light comic relief which is so abundant on SB forums as many don't seem to have managed to ascend out of the quarry yet to discover that there is another world out there where experience makes the rules.

For the record, I have done many dives on air in the tropics to around 200' with another poster on this thread without any detrimental effects, detrimental effects, detrim.....

However, I would never consider doing the same type of dive in colder conditions off Sydney as they would not be as pleasant and narcosis makes a dive pointless IMO, however YMMV.

 

[geoff w]

What? Why on earth would you risk stationary staged deco bottles in OW? Want to know what happens when you do that???? Read about the Rouses. Or the many others whom made the same dumb choice.

I originally read about the Rouses in Shadow Divers, shaking my head at the time how they could do so many really dumb things. And read some more based on your comment, including Accident Analysis | Doppler's Tech Diving Blog Is there any difference between doing a "recreational" deco dive at Tufi, like I originally asked about, or going on a guided recreational dive through some of the caves in Cozumel, Playa del Carmen or Akumal? Both are typically considered technical dives due to overhead restrictions, but guided and targeted toward advanced recreational divers? Equally foolhardy, or without the deco obligation lower risk? Something I have always wanted to do, but again, I have absolutely zero interest in getting cave certified and not something I would intend to do more than on one trip as a "dive tourist". Personally the guided cavern dive scares me more than the guided deco dive

 

[gcarter]

I have absolutely zero desire to do deco dives on a regular basis. I asked my question because this is probably one of the only times I would do a deco dive in my life, knowing in advance I would do it. I dive with lots of tech divers, those with little plastic cards certifying them as having taken the AD/DP class, as well as a few I have real respect for. Frankly, taking the class and then never / rarely using the training scares me more than not getting the training in the first place, because skills decay when not used, and it seems like technical diving skills decay more rapidly than recreational skills. I've never understood the logic of tech diving certifications not expiring if not regularly dived and practiced. The majority of my dives (a few times a week) are So Cal shore dives, frequently through surf, so the thought of a multiple tanks is not only unappealing (e.g., walking across stretches of sandy beaches with doubles), but also greater risk due to entry / exit with waves. Shore dive depths here rarely exceed 60 ft, so little chance to practice deco procedures. When I do boat dives, I want to see interesting stuff, and figure I'll never even get to do enough recreational dives to see everything I'd like to

I find this an interesting position to take - because you only expect to do this once, and because you believe the skills will atrophy over time if you do not continue to use them, you feel it safer to not get the training for the dive that is actually in front of you?

I don't know if that is what you intended, but it is what a plain reading of what you wrote presents.

 

[Foxfish]

Allowing for a 3 minute time interval at depth prior to the ascent, I estimate the total air required to surface in an emergency would be 330 b ie. multiple AL 80 tanks. This assumes zero nitrogen loading prior to the dive. Your deco stops may be much longer depending on your previous profile. I'd want to carry an independent gas supply in these circumstances. Maybe doubles or twin side mounts.

At the maximum depth breathing at 60 L/hr (emergency buddy breathing rate) you use up half the air for one tank in 3.5 minutes.

Things you may not have done before include diving to greater depths outside recreational limits, diving deco, using an independent gas supply and relying on stage bottles for your ascent and emergency backup. So you'd be doing a pinnacle dive in PNG without the required training, experience or conditioning.

What would I do? Stick to the shallow dives.

 

[geoff w]

... Diving zealots will have you in a constant state of training to prevent the sky from falling on you and have you looking like a cluster f$%k with redundant this, that and the other waiting for that day to come........which is fine if you don't have a life or friends to distract you.
I liken this kind of diving to driving a car whilst towing a deployed parachute just in case the brakes fail, both of which do wonders for your air and fuel consumption.

The OPs post had a familiar (to me) ring to it so I checked his credentials and discovered that he had extensive tropical diving experience in various locations and would know that conventional rules of narcosis and sac don't apply when diving in warm tropical water. I figured that he was posing a rhetorical question in order to get some light comic relief which is so abundant on SB forums as many don't seem to have managed to ascend out of the quarry yet to discover that there is another world out there where experience makes the rules.

For the record, I have done many dives on air in the tropics to around 200' with another poster on this thread without any detrimental effects, detrimental effects, detrim.....

However, I would never consider doing the same type of dive in colder conditions off Sydney as they would not be as pleasant and narcosis makes a dive pointless IMO, however YMMV.

I asked as a very serious question, and not rhetorical. PNG was never on my bucket list, even after talking to the friend instigating the Tufi trip, but our other friends who dived the Coolidge while cruising in Vanuatu did make it quite appealing. Unfortunately, they're not taking off to go cruising again for at least another year.

Conventional rules for narcosis and SAC still apply in warm tropical water, just like in cold water where I live, just that rates are more conducive to diving in the warmer waters - you still breathe a lot more air at 130 feet than at 30 feet, just not quite as much when it's warm.

I fully expected to get the textbook answer of "get proper training or die", as well as the "sure, go for it", but got a lot of good responses and insights in everyone's responses. I don't think there is any right answer, and from my personal experience I don't think the tech diver answer is necessarily always right.

At last night's PADI member forum, I was talking to an acquaintance who recently went diving near where I live; he is a very experienced technical instructor and excellent diver. It was a shore dive with roughly a 400 yard surface swim to a few pinnacles just breaking the surface. I told him I was impressed he did it with such a big tidal change (on a point, so currents can be brutal) and he said it was the first time he ever did the dive. Then he proceeded to tell me he was in a dry suit, with doubles and had a scooter because it was such a far swim. I was amazed he walked across the sand carrying all that gear, and would do a surf entry in a drysuit because of additional bulkiness getting out through the surf, potential for a wave popping a seal and leaking, and additional drag for the trip out and back. This was for a straightforward but relatively advanced shore dive easily accomplished with any recreational gear configuration for what is typically 30-45 minutes at the site (and scooters are useless for really exploring the details in the nooks and crannies); the surface swim out is typically 12-15 minutes, maximum depth less than 60 feet, and return to exit point by underwater navigation. His response was that was his normal configuration. If anything, it appeared all the redundancy added complexity and risk in this case, rather than reducing it. I'm sure this is counter to prevailing wisdom, but in this case the tech approach didn't pass my common sense test

---------- Post added January 29th, 2014 at 06:49 PM ----------

I find this an interesting position to take - because you only expect to do this once, and because you believe the skills will atrophy over time if you do not continue to use them, you feel it safer to not get the training for the dive that is actually in front of you?

I don't know if that is what you intended, but it is what a plain reading of what you wrote presents.

Not at all the intent. I'm sure I would be incrementally safer getting deco procedure training for the dive I originally asked about. Not doing another deco dive for many years, and then one day deciding to go out and do another deco dive because I'm trained and certified is what scares me more. Very unlikely I would do something that foolish, and clearly a flaw with any lifetime scuba certifications, but I've observed plenty of previously proficient divers flail around miserably because they can no longer do skills they were previously trained for. I would expect skills requiring higher levels of competency, such as planning and executing deco procedures, would atrophy more quickly than being able to accomplish something like following a guide on a resort dive after not having dived for several years

 

[drrich2]

If anything, it appeared all the redundancy added complexity and risk in this case, rather than reducing it. I'm sure this is counter to prevailing wisdom, but in this case the tech approach didn't pass my common sense test

Here we go. You analyzed a given situation, applying your knowledge and experience, to consider the options, the pro.s and con.s of each, and arrived at a conclusion about what the best way for you to approach that dive would be. Maybe even for the other guy to approach it.

Assuming you have the depth of relevant knowledge and experience to make that determination, you make an informed decision.

Much of the purpose of getting some deco. training beforehand is so that you can do the same thing on the deco. deep dives you propose to do.

You don't trust the judgment of a personal acquaintance you identify as a very experienced technical instructor and excellent diver in planning and carrying out a challenging shore dive in the best manner available (though he did come back from the dive fine).

Yet you propose to trust people you as of yet presumably know less to take you on a decompression deep dive. And will your wife also be on this dive?

Geoff, I've tagged along on trust me dives of a different nature in the past, and I'm not dishing out any disrespect here. I'm just suggesting you think about it, and whatever you decide to dive, I hope it works out for you.

Richard.

 

[gcarter]

Not at all the intent. I'm sure I would be incrementally safer getting deco procedure training for the dive I originally asked about. Not doing another deco dive for many years, and then one day deciding to go out and do another deco dive because I'm trained and certified is what scares me more. Very unlikely I would do something that foolish, and clearly a flaw with any lifetime scuba certifications, but I've observed plenty of previously proficient divers flail around miserably because they can no longer do skills they were previously trained for. I would expect skills requiring higher levels of competency, such as planning and executing deco procedures, would atrophy more quickly than being able to accomplish something like following a guide on a resort dive after not having dived for several years

Glad to hear that. I would still be more focused on whether I felt properly prepared for the dive in front of me though. To me the rest doesn't matter right now, no matter how true / accurate an assessment it is. Every dive is an opportunity to ask the question whether you are prepared for this dive on this day and requires a frank assessment and answer. If done honestly, what you have expressed becomes a non-issue. My five cents (no more pennies in Canada).

All that to say, I would stick to the shallower dives

 

[TSandM]

Allowing for a 3 minute time interval at depth prior to the ascent, I estimate the total air required to surface in an emergency would be 330 b ie. multiple AL 80 tanks. This assumes zero nitrogen loading prior to the dive. Your deco stops may be much longer depending on your previous profile. I'd want to carry an independent gas supply in these circumstances. Maybe doubles or twin side mounts.

???? It is quite possible to get two people to the surface with a single Al80, if the other diver has enough reserve. To get to 70 feet using a fairly conservative ascent strategy requires 40 cf, or about 1600 psi.

BTW, to the OP, I have technical training and have done a modest number of technical dives, so the whole idea of doing deco doesn't bother me at all. It's just the conditions of the dives you described that put me off.

 

[Eric Sedletzky]

Without adding to the lively discussion in a couple of other recent threads about recreational divers going into deco, I am now potentially faced with a good dilema on the subject. I'm a relatively competent and experienced recreational diver with absolutely no plans of getting into technical diving. A friend invited us along with a number of her other buddies to go to Tufi Resort in PNG; if we take care of the airfare, this friend will pick up accommodations for everyone who joins her (and before anyone asks, I'm positive the offer does not extent to online friends of friends from Scubaboard!)

I started looking at the Tufi web site to find out about diving there, and there are some interesting wrecks; see Wreckdiving for the descriptions. These dives are clearly geared toward recreational divers, but are described as having only 10 minutes of bottom time and "a decompression dive with max depth 45m. Deco stops are compulsory and surface interval of 4 hours is mandatory before the second dive." There's even a muck dive off the wharf that includes a Land Rover on the bottom also described as a deco dive

What would you do in my situation and why? Just do the shallow muck diving and local reefs? Blindly follow their prescribed profile? Take a deco procedures class before going? These are 100 minute dives with stringent preplanned safety stops along the way, so I presume the resort has done this before, with plenty of tanks staged for those who can't make an Al80 last the whole dive, therefore assume there is some additional air besides the single on my back. Unfortunately they don't appear to have nitrox there. It sounds like there is a chamber in PNG

There's some stuff that bothers me about this situation.
"Staged tanks for those that can't make an AL 80 last the whole dive"? Are you telling me they are setting additional air at different locations throughout the dive? You mean like on an up line?
We never did anything like that. I was trained to pack everything I was going to need period. What happens if the plan goes wrong and you don't make it to the next tank for some reason?
If you ask me, take at least a deco proceedures class and an advanced nitrox class with it (they go hand in hand). That will give you the basics at least to do a dive like that safely (some may argue that that would be a mix dive) I don't think so, at least not for me.
I wouldn't do it without a set of doubles and a slung bottle of 50/50, and the rest of the stuff needed and experience and training on how to use it.
And, I would make sure there was a working 02 kit with a plentiful supply just in case.
People have gotten screwed up doing a lot less in remote locations.

I personally would never allow myself to be lead on a dive like that without knowing (technically) what it is I'm getting into.

 

[GrimSleeper]

Whether the 'Yer gunna die' chorus like it or not, exactly the kind of dive you describe is carried out without mishap by thousands of divers every year in tropical locations. Unlike most of those divers, you seem to have enough knowledge to at least start asking the right questions.

Is it safe? For a given value of safe, yes, although if it starts to go south you almost certainly WILL be relying on others to get you out of there.

Should you do it? Up to you. You seem to have a pretty good handle on the risks. Lots of people do it and don't die. That doesn't make it 'right', but it does make it empirically reasonable to expect a good outcome.

Would I do it? Are you kidding? The 'Blackjack' and only one shot at it? Sure. Without a moment's hesitation. Mind you, I know I can do 10 minutes' bottom time at 50m on a single Al80 and get back on the boat with 40 bar or so left, providing nothing goes wrong. On the other hand, I generally do anything past 40m in sidemount these days, just in case.