Is a minimum deco style profile possible while DMing in a resort location?

[Charlie99]

Tollie- What you are saying makes perfect sense, my only real concern is with repetative diving. I have seen some DMs take multiple groups of divers out on the same day and get a lot of dives in in one day. While the divers in each group go no where near NDLs that DM may begin to push the limits.

You also need to take into account that you will most likely be diving air, not nitrox.

You could try PM'ing Uncle Pug or Boomx5 for some real life info on how DIR profiles worked on some dive trips in Maui. We were together on a 3 tank dive in Molokini Maui a couple years ago where they did a 3 tank dive on air. The first dive was a 130' multilevel, 2nd a shallower multilevel, the 3rd dive was a 65' flat bottomed dive. Surface intervals were around an hour.

They didn't have any apparent problems using DIR profiles, other than they ended up doing a shallow hang for another 5 or 10 minutes after everyone else had gotten out of the water.

While having to do longer stops wasn't a problem for customers --- we just hung around waiting for them to surface --- that might not work out for a DM.

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As another poster has suggested, you should get specific with your intended location. My experience is that on most reef dives, the DMs go for a nice multilevel dive/ascent which should mesh nicely with any minimum deco / DIR profile. The problem, if any, is most like to happen in locations where there isn't anything to look at between the bottom and the surface.

Charlie Allen

 

[Tollie]

Jess,

An attitude towards safety for guests and the DM would be a criteria for me to work for an operation. That is if operator that I worked for was to schedual trips that would put me at the edge through aggressive repetitive dives repeatedly I would think twice about working for them. Eventualy the odds will catch up with you. One day your body will not be up to it and you will take a hit.

So as a DM you need to take care of yourself... in the same way that an instructor with several students who are doing CESA's needs to think twice about repeatedly bouncing. Recreational diving is more forgiving then Technical diving but even for Rec dives there is a limit.

An expression I was taught when I became a boat driver is: "When there is doubt... there is no doubt." Which means if you are not sure about your own repetitive dives and the profiles you, personaly, are running... then you should not be doing them.

/philosophy
I dont want to die in the water... and I want to keep diving and doing the things I love. So for me a positive attitude toward dive safety is key... its also the key to enjoying what you do as a DM. If you have it in the back of your mind that things may not turn out so well you just cant be effective as a Dive Leader... and thus enabling your guests to have fun, see things anew and grow as divers.
/philosophy

 

[RTodd]

And what do you do when something happens and you need to intervene? just to pick an example, suppose you're in the middle of leading your clients on a "slow ascent" and one of them gets a free-flow and bolts to the surface?

Sure it's possible to lead people anywhere you want them to go as long as nothing odd happens.

R..

Just in case the people that are getting any benefit from this don't know the answer to this question, the answer is the same thing I would do on a dive with a 1 hour deco obligation. DIR concepts are team oriented. If you are putting yourself in a situation to look after a larger group of people, that mindset does not change. you take care of the problem and then worry about whether deco needs to be dealt with. On a "no-deco" open water dive, the answer is usually that it doesn't.

For those worried about clients being bothered by minimum deco, pay more attention to how the better resort DMs are guiding dives in the first place. As far as needing a computer, some operations may require you to have one on your wrist. However, if you are going to dive the same 20 or so sites/ profiles every day and still need a computer to figure out where you are from a deco standpoint, the DIR concept of deco may not be for you.

 

[JessH]

Jess - it sounds as if you are not comfortable using depth averaging to keep track of your profiles and ascents and deco without using a computer. If that's the case, you should probably at least have a computer as a backup

Well you are absolutely right about that, but it will be a minimum of 6 months before I have the oportunity to actually do this, and I am hoping that by then I will be much more comfortable with these things. Right now it is more of a theoretical question that I was contemplating. Although I am hoping that it will become reality sooner than later.

~Jess

 

[JessH]

Not sure which min deco style you use, but the ones I've seen require only 90 min to clear completely which is pretty normal between resort dives, and the rules I was thaught don't require even that or track nitrogen loading so I don't see how repetitive dives would be an issue.

I was refering to situations in which you violate the rules associated with the min deco style, such as coming up quicker in order to help another diver, etc... In situations such as that you would of course add extra padding some place, but you would basically have to make up how much and where. Of course computers aren't necessarily going to come up with any better of an answer for that. A friend of mine got bent like that and he did exactly what his computer told him to do.

I am actually starting to think that minimum deco style might be better for handling these unexpected situations than most computers...

~Jess

 

[Diver0001]

you take care of the problem and then worry about whether deco needs to be dealt with. On a "no-deco" open water dive, the answer is usually that it doesn't.

.

Actually, that was my point, Richard. If you assume that you have lead a whole group of inexperienced divers into a deco situation and one of them bolts, then you, the diver in question and probably a number of other divers with no idea how to continue without you may end up on the surface with undone deco.

Dealing with something like that isn't trivial, especially when dealing with a group of beginners. When DM-ing beginners, you may act like the leader but you are in a responsive mode and in many ways you are more the follower than the leader--more about *their* process than yours. In the context of DM-ing in general and at resorts in particular, it's highly unlikely that you'll ever have divers in the water who are good enough divers to spontaneously form anything remotely resembling a team.

You may think it's stupid and strokish but raising the discussion, as naive as you think it is, may actually benefit the OP in his process of preparing for this. On the same token, it may *not* but at least someone got up to bat and tried to discuss it instead of trying act like the questin doesn't exist.

I didn't get off on this tangent for nothing. The OP asked this question and commented that he felt the that tables were "too conservative" to which I assumed he meant tht the NDL's were too short for the dives he felt he needed to do. I focused on this point because he's going to be in a position that dragging expecting beginners anywhere near the NDL is going to be problematic and over the NDL will be very risky, in more than one way. And that's what I thought he was talking about.

If he has good enough control to avoid exceeding the NDL's then the whole issue is moot and we only have a discussion about how fast he likes to ascend, which isn't very interesting as Snowbear already pointed out.

R..

 

[GDI]

Hopefully I'm not off topic here but in a nutshell Yes they can

Resort DM's have been making these sort of dives for years long before computers came onto the scene. Tables were all they had. In fact many really didn't bother to look at the tables after a time because they just kept repeating the same dives day after day and without incident. This we keep in mind that most resorts are dealing with basic skilled level divers in that they, the divers, know to put a reg in their mouth and breathe. The DM's must work with this minimal skill level as a starting attitude. As one goes through the week of diving at a resort and they appear to be proficient divers then the DM's don't focus on them as much as they do on the lesser skilled divers.
Can you do these principles of "minimum deco" without computers? Can you do them using tables staying within NDL? Can you do them without much impact to a group of divers such as on a guided resort dive, personal safety? Yes you can.

Define "minimum deco", Is this just another term for "multi level" (with a twist)?

Every dive, as already mentioned, is a decompression dive and for that matter every dive is a "virtual" overhead dive subject to the depth you go to.

No one can predict with any certainty under what conditions on any given dive who will or will not get bent .


Divers who were simply doing multi level dives during recreational diving were using what commercial divers had been doing for years. If a resort customer were to ascend using a different principle to that of the DM or group as a whole most likely would not have any issues with the charter boat as long as a perception of safety was observed. A diver diving on tables can be in the water enjoying the dive just as long as a computer diver, if the diver is using multi level/minimum deco principles. A DM leading these types of dives using tables can do so with a degree of acceptable safety or risk if your prefer.

Computers are in fact nothing more then a continuous calculating algorithm of a dive table. In a basic physiological sense from the body's point of view as it pertains to DCS one is no better then the other. A computer just facilitates easier dive planning

 

[dsteding]

I didn't get off on this tangent for nothing. The OP asked this question and commented that he felt the that tables were "too conservative" to which I assumed he meant tht the NDL's were too short for the dives he felt he needed to do. I focused on this point because he's going to be in a position that dragging expecting beginners anywhere near the NDL is going to be problematic and over the NDL will be very risky, in more than one way. And that's what I thought he was talking about.

If he has good enough control to avoid exceeding the NDL's then the whole issue is moot and we only have a discussion about how fast he likes to ascend, which isn't very interesting as Snowbear already pointed out.

R..

Ahh, I think here lies the issue-the OP is referring to tables being "too conservative" because they assume square profile dives, and he's going to be doing 5 non-square profile dives a day. A computer will take this into account, as will diving GUE/DIR min deco profiles . . . characterized by some as "multilevel" dives, but which seem to me to be deep stops to slow bubble formation (I'm still learning here-so someone else may chime in). Regardless, given the slow ascent rate, they are not square profiles, so standard tables would indeed be overly conservative.

I don't think he's talking about exceeding table NDLs, so the issue isn't leading new divers into deco--obviously, that isn't a wise thing to do--but leading newer divers using a different ascent profile, one that may not be understood by the dive op.

Diver0001, I just think there are some wires crossed here, maybe this clarifies a bit.

 

[Diver0001]

Diver0001, I just think there are some wires crossed here, maybe this clarifies a bit.

God, I hope you're wrong.... Otherwise we just made 60 posts about a non-issue.

R..

 

[dsteding]

God, I hope you're wrong.... Otherwise we just made 60 posts about a non-issue.

R..

No-still an issue, just not one of NDLs, at least directly. GUE trained divers (of which I am not one-yet-so someone that is please correct me if I am wrong-this is from diving with such divers) will have an ascent profile that has 1 minute stops at 30, 20, and 10 feet.

In addition, I believe deep stops for 1 minute start at 75% of your maximum depth and are repeated for each 10 feet.

This is much different than say, the PADI ascent of "don't go faster than your bubbles" or 60 fpm (now seems to be going to 30 fpm). The net result for a DM would be that your clients are left behind as they rocket to the surface as you do what is essentially a 10 fpm ascent . . .

I think the dual issues presented by this thread are these:

1) the slower ascent is taken into account by a computer as a multi-level dive. Since GUE trains divers not to rely on computers, using square profile tables would treat a dive with a ten minute ascent as one that is much longer at depth-this is the conservatism issue associated with purely diving tables. I guess this could be considered an NDL issue in one sense.

2) as noted above, people wouldn't necessarily follow these profiles, or be familiar with them. I think that is what Snowbear is driving at-when she has done dives in the past with non-GUE trained divers, they've asked her about her ascents and some have even adopted them with good results . . .

I will say that I did a series of ascents with a GUE trained driver a while back on a charter, and besides feeling great after the dives, they are good buoyancy practice and skill development.