No Deco rules - Local Island Diving - Maldives

[Heat Miser]

I have just spent a week open circuit diving in the Maldives on a local island.

My question is do the local rules regarding, no deco diving and 1 hour maximum run time, encourage local divers to adopt less safe dive profiles then they would elswhere in the world.?

Because they don't want their computer to go into deco, most of the local divers I dived with, run the least conservative settings, which on a Garmin is a GF 45/95. This is regardless of depth (which in the Maldives is limited to 30m) and regardless of surface interval, (which was typically 1 hour)

I found that after the second dive, particularly, after say two dives to 29 meters and 1 hour surface interval, that there were big differences in the guides dive profile, to what i wanted to do running GF 50/70. The water is warm and often there is a lot of fish life to see at 3-6m, even floating in the blue because vis can be 30 meters (100 feet). Generally I would just get my guide to do the stops, I wanted to do.

But I wonder if there are any stats on local's getting DCS. It seems to me that they are willing to really dive to the limits of the rules i.e, 30m, <1h total run time, no deco and perhaps they may be better served, getting rid of the no deco, < 1hour rules, to encourage more conservative gradient factor/model adoption.

thoughts?

 

[JustSurfaceInterval]

I doubt that anyone will spend 1 h at 30 m. Certainly not if this is his 2nd or 3rd dive of the day.
Local divers, you certainly mean Dive Masters doing that for a living, may be inclined to go for less conservative profiles - i would not call that less safe - but that won't be really usefull if their guests are on a more conservative profile. The guide will have to go up and stay with the guest(s) even if his computer does not show a deco stop.
But i don't know of any stats on deco related incidents with DM or tourists in the Maledives.

 

[boulderjohn]

If you are running 50/70 on a NDL dive, your NDL times will be very short. That is a very conservative setting. The more aggressive settings are still within standard limits, and they should be very safe. I would not expect a high incidence of DCS. Where I do most of my NDL diving, we rarely get the luxury of a one hour surface interval, and people aren't getting bent right and left.

If you are using a computer that has a SurfGF feature, set the computer for a more aggressive profile and then make sure your SurfGF is below a level you like before surfacing. For example, on an NDL dive, I will typically hang on my safety stop until it goes below 70.

 

[Heat Miser]

If you are using a compute that has a SurfGF feature, set the computer for a more aggressive profile and then make sure your SurfGF is below a level you like before surfacing. For example, on an NDL dive, I will typically hang on my safety stop until it goes below 70.

Yes thats something similar to what I have been doing, Except I have been letting the computer with GF 50/70 go into deco, and then do the subsequent stops (9m and 6m) to get to SurfGF 70 on surfacing. Whereas the locals (set 45/95) are skipping that second part (the stops, apart from the 3 min safety @ 5) and getting out 6-7 minutes early.

Its just perspective I guess, Im looking at it from a AN/DP perspective, they are looking at it from a NDL perspective. It does seem a touch unusual to me though, but they have warm weather and the boldness of youth on their side.

 

[boulderjohn]

Yes thats something similar to what I have been doing, Except I have been letting the computer with GF 50/70 go into deco, and then do the subsequent stops (9m and 6m) to get to SurfGF 70 on surfacing. Whereas the locals (set 45/95) are skipping that second part (the stops, apart from the 3 min safety) and getting out 6-7 minutes early.

Its just perspective I guess, Im looking at it from a AN/DP perspective, they are looking at it from a NDL perspective.

So your question boils down to this: how often do people get bent diving within NDLs but closer to the limits?

 

[Heat Miser]

So your question boils down to this: how often do people get bent diving within NDLs but closer to the limits?

yes ... I wonder if there are any stats on local's getting DCS. It seems to me that they are willing to really dive to the limits of the rules ... because the rules are conservative <30m, <1hour, no Deco.

the analogy is like driving a car 20 MPH in a 15 MPH zone

 

[Karlstumke]

Look I don’t get the 30m rule at all. If you qualified to do 40 why restrict to 30? Many of the dives are above 30 min so u just b#£hit everyone by marking 30m on dive sheet. I can think of kandooma Thila generally 32-35, kuda Giri over 30m andd fuvamalsh..weeeell

 

[Pearlman]

Possibly because the only chamber in Maldives is far far away by boat ride and getting an air-ambulance is also going to take many hours? The line of thinking here may be a simplistic “Deco divers are more likely to get bent and land an emergency situation”…

I recall a story narrated by the director on an LOB about a female diver that got bent the previous week before we boarded - she had to make a speedboat ride that took hours to arrange and then the air ambulance was another 4-5 hours away. I don’t remember the exact details but it was maybe 12 hours before she reached the chamber at great financial expense. Cost her more than her vacation upfront I heard (until DAN or whatever insurance refunded).

I typically dive 3 dives a day with conservative settings of -2 on my Suunto Eon Core and I’ve never had a problem in last 75 dives or so with it. But that’s for the strictly recreational dives - when I learn deco diving next year I plan to keep it strictly at 0 default until I figure I need to be more conservative or not. Not inclined to test the algorithm liberally for deco dives even in theory the way I think about it right now.

 

[JustSurfaceInterval]

Well.. Karl... i remember the glorious days when limit was at 40 m and we spend some time at Kandooma Thila and Kuda Giri...
We had one guy bragging having been down to 45 m. Guess what? the DM in charge checked his computer and banned him from diving for the rest of his holidays. Those were the days...
But that's off topic here and perhaps a wider discussion whether or not rules have to be followed.

 

[scubadada]

Hi @Heat Miser

The first, clean dive NDL for a GF high of 95 on 32% to 100 ft (30 m) is only 26 min. For your GF high of 70 it is something like 15 min. To give us an idea about the overall profile, what were the average depths? I would imagine they were generally no deeper than 15-20 m (50-65 ft) or many of the divers would have exceeded NDL on some of the dives near an hour in duration.

I'm another diver who dives reasonably aggressive GFs but uses SurfGF to plan surfacing.

Hi @Pearlman

Your Suunto Eon Core at -2 runs very similarly to a GF high of 95. @Diving Dubai has considerable experience and has posted about it.