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

[Snowbear]

That's fine for the shallow stops - what about the deeper stops? (in blue water..with probable currents)

Actually, I was outlining it for the entire ascent.

Lot's of people then take as long as they like to do the last 5 meters. Meanwhile the boat has seen your SS and is ready for you when you surface. Coming up from a 24 meter reef through blue water slowly can really push you a long way away before you shoot your bag.

If you can take as long as you want from 5m, then why not shoot your bag when you leave the reef and take as long as you want to ascend? That's how we were doing it in Palau. Most of the divers just popped off the reef, ascended at 60-100 fpm (really!:11: ), did their 3 or 5 or however long their computers told them to and the boat came and got them. Those of us (there were 5 'DIR' divers on that boat) who made longer ascents just didn't end up that much farther out than the others.... though as standard practice, we shot bags so the boat could follow us if needed.

Here's the story of the gal who bent herself on that trip following her computer. She and her husband tried my suggestions for the rest of the trip and ended up feeling fantastic... and they weren't drifting away from the reef any farther than anyone else either....

The time spent ascending a 'minimum deco profile' vs maximun ascent rate and 'safety stopping' really isn't that much different. And is much, much safer. IMHO of course

 

[Snowbear]

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.

~Jess

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

 

[*Floater*]

Diver0001 - Resort diving, often involves many repetative dives in a day and non square profiles. I have found that you will run out of bottom time with NAUI tables long before you would with either a computer or a minimum deco model. The minimum deco model seems much better for repetative dives since it gives you credit for offgassing more underwater than rec tables which assume a close to worst case deco situation.(remember that this is all still "NDL" diving)

I've also tried it. I took about 30 dives I had done using my computer before learning depth averaging and min deco rules and went back to calculate whether min deco was violated on any of those dives (other than ascents). It was not, except on one dive which was a planned deco dive anyway. Also, my computer is a versa pro which is considered liberal, though I don't necessarily dive it to the limit every dive.

One drawback to using a minimum deco method while DMing seems to be that you may have to routinely violate it in order to help other divers. I know that you can counter this with padding, etc, but It seems that you may end up in a very murky situation very quickly.

If you need to make a rapid ascent, then you should assume more bubbling and take appropriate steps in the next dives to make sure it won't be an issue. If anything, I'd assume DIR techniques would be better suited for this type of ascent violation than many computer algorithms.

It seems to me now that doing a deep stop and a slower minimum deco style ascent would not be a problem, but that keeping track of nitrogen loading using rules such as those taught by GUE or minimum deco tables such as the dir-diver ones could become one. I guess it may be necessary to find a suitable comptuer to run as backup. Thoughts?

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.

<snip>

Is using a Suunto possible while DMing in a resort location? This would be a tougher question imo. What do DM's do when the client dives a Cochran or Oceanic and wants to spend another 20 min on the 5th dive of the day when the DM's Suunto is already in deco?

Anyway, my DIRF instructor doesn't use a computer and still manages to DM just fine. He said most people don't even notice him do the min deco and if he enters deco for some unplanned reason, then he just adds that to the ascent.

 

[Diver0001]

I hate to answer this thread since it will be difficult to do without using the word stroke about 50 times. But, the answer to your question is yes, it is very easy. My interaction with divemasters in the south pacific is pretty much limited to between dives on the boat. While I can say the average quality is lower in this part of the world and their ascent strategies are probably not as good, it would still be very doable. When guiding, the clients follow you. If you lead them on a slow gradual ascent, they will do it. In locations where their are more professional local DMs, such as Cozumel, you will see this. While these guys don't do exact 1 minute stop and move, the better ones do effectively do a nice gradual ascent up to 15' and many pull a 10' stop as well. Their gear and attitude may be a disaster in other areas, but people that do this long enough do figure out what keeps you from feeling like crap after a day of diving.

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..

 

[Diver0001]

Diver0001 - Being that this is the DIR forum, 'every dive is a deco dive.'

'Minimum deco' does not necessarily mean a diver has incurred a 'deco obligation' beyond that normally incurred on any recreational, so-called 'NDL' dive.

I know that. When I wrote that I was thinking about an experience I had last year diving for a weekend with a DIR friend of mine. We made 6 dives together at depths at around 30 metres using minimum deco profiles. He didn't have a computer, but I did.

What interested me was that we went over the NDL 6 times (the biggest one was 10 minutes) and while it's true that the minimum deco profile eliminates that obligation before you get to the surface he couldn't tell me when we went over the NDL, how big the deco obligation got or at what point during the ascent we were clear. In terms of DIR the whole discussion of NDL's and deco obligations clearing might not make sense, but either way it would have been very unhealthy for him to have surfaced at some points during thost dives....

In the context of DM-ing that would give me alarm bells for two reasons. (1) you could lose access to the surface, even if you don't always and (2) you may drag inexperienced and ill prepared divers into a situation that they have lost access to the surface too...

That was my point. As far as I know it's not part of minimum deco thinking to ensure that you don't incur a deco obligation while for a DM not losing access to the surface is essential to maintaining safety. Surely you can see that there is a conflict between those two paradigms.

That's not to say that you can't make minimum deco type ascents while using tables or a computer to make sure you didn't go over the NDL..... of course that's possible and you'd need to do something like that, I think, to build in adequate conservatism in the context of DM-ing.

R..

 

[Snowbear]

As far as I know it's not part of minimum deco thinking to ensure that you don't incur a deco obligation while for a DM not losing access to the surface is essential to maintaining safety.

Actually - for single tank, non-tech diving, AFAIK, it absolutely IS part of the DIR 'minimum deco thinking' to ensure the 'NDL' is not exceeded.

This would be especially so in the context of a DM leading multiple, recreational, NDL dive profiles.

 

[Snowbear]

I know that. When I wrote that I was thinking about an experience I had last year diving for a weekend with a DIR friend of mine. We made 6 dives together at depths at around 30 metres using minimum deco profiles. He didn't have a computer, but I did.

What interested me was that we went over the NDL 6 times (the biggest one was 10 minutes) and while it's true that the minimum deco profile eliminates that obligation before you get to the surface he couldn't tell me when we went over the NDL, how big the deco obligation got or at what point during the ascent we were clear. In terms of DIR the whole discussion of NDL's and deco obligations clearing might not make sense, but either way it would have been very unhealthy for him to have surfaced at some points during thost dives....

Sounds like you DIR buddy needs a review

 

[Diver0001]

Sounds like you DIR buddy needs a review

Probably..... I wonder if it was less a matter of "didn't know" and more a matter of "didn't care"...

I was just thinking about how to get the point across about DM-ing in the grey zone around the NDL's.

I think it's fair to say that many (most?) people are trained to fear the NDLs and ride their computers. Some of them may even freak out and *surface* if their computer flips to zero..... I've seen people get very stressed when the computer gets in the "yellow" zone and refuse to surface before it flips back into the "green"..... This is about as much knowledge as a lot of people have about deco and profiles and as a DM, you have to understand and account for this fact.

That's not to say that minimum deco is bad or can't be applied, but you would need to address some of these issues/risks.

R..

 

[Snowbear]

That's not to say that minimum deco is bad or can't be applied, but you would need to address some of these issues/risks.

Good points, Diver0001. But still I think (from putting it into actual practice ) that addressing those issues/risks is not that big of a deal to someone who actually understands the depth averaging, NDL guidlines and the so-called 'minimum deco' style of dealing with ascents. Once a diver has a pretty good (i.e. thorough) understanding of what's going on, it's really not any more difficult to address things like a dingbat client that messed up your profile for a few minutes than it would be to address a computer that 'went into deco' from too fast an ascent rate or too long/deep a profile.

 

[Diver0001]

it's really not any more difficult to address things like a dingbat client that messed up your profile for a few minutes than it would be to address a computer that 'went into deco' from too fast an ascent rate or too long/deep a profile.

Yeah, That thought occurred to me too. It's quite possible that if i had a little more experience with it that I would see the risks differently. I just thought these were interesting discussion points when I read the opening post.

R..