gasgirl
Contributor
Attention: I am seeking opinions from divers who have first hand experience with Suunto computers only please! (For those who do not dive with Suuntos and do not know about the problems with the over-conservative algorithms that penalize repetitive dives with short surface intervals, please refrain from responding with non-productive critical comments!)
Brief background:
Shortly after purchasing my Suunto Cobra, I recall being advised by an instructor in Grand Cayman that it would be fine to incur a deco obligation at depth up to 10 minutes as it would clear during my multi-level profile as I ascended and did my safety stop. I opted not to voluntarily put my new computer into deco on that trip but I was diving in conditions and sites that easily allowed me to modify my depth to be shallower that the rest of the group.
Shortly after that, I switched to diving Nitrox, and I no longer came even close to my NDL times on my repetiitve dives, and so I never had issues with Suunto being too conservative even when we were doing five dives a day (albeit with longer surface intervals than 60 minutes) on any of our subsequent dive trips.
Fast forward to the present:
We will be heading to Cozumel in a couple of weeks and based on what I reviewed from other trip reports, I am concerned that the dive profiles for our two tank boat dives we wil be doing may be problematic for us as we are diving with Suunto computers.
Because of conditions specific to Cozumel (ie. swim throughs at depth and possible strong currents), I am anticipating that the first dive of the day in Cozumel may be at a depth greater than the MOD for EAN 32% so we were planning on diving air. Then we are assuming that there will be a very short 30 minute surface interval before the second dive, so we are planning to dive wither EAN 32% or EAN 36% to help extend our NDL time for this second dive. However, my understanding is that Suuntos really impose serious penalties on the NDL's for surface intervals shorter than 60 minutes.
My questions for Nitrox divers in Cozumel are:
1. Do people commonly dive air on the first tank and then EAN on the second tank in Cozumel? ie. Will using EAN give us a more reasonable NDL on this second dive?
2. Is yes, would you recommend diving EAN 32% or 36% giving the typical second dive profiles in Cozumel?
3. Is anyone aware of oxygen toxicity problems diving with Nitrox on the first deep dive?
My questions for those familiar with Suunto computers are :
1. Would you allow the Suunto computer to go into deco and assume it will clear as you slowly ascend (10 ft/min) with mulitlevel stops for several minutes at 50 and 40 and 30 feet?
2. If yes, what is the maximum deco obligation that you would incur (assuming, of course, that this still falls within the gas plan)?
FWIW, I did do a search on SB forum and found numerous comments condoning this type of practice to counter the overly conservative limits of the algorithm. For example, here is a quote from lamont in another thread:
"Realistically on a Suunto with 5 minutes showing (2 mins mandatory + 3 mins safety stop) you're not in much danger at all. You can probably even go across that by another 5 mins at depth and while the Suunto will probably be telling you 10+ mins of deco to do, you'd be fine blowing it off if the absolute worst case happened to you.
So yes, I realize that I have no technical training, and that I am diving a single AL80 tank, but I am also getting the impression that in the worst case scenario, it is the computer that will get bent, and the dive plan is still within safe recreational limits on pretty much any other computer.
I am hoping to get responses that will help me figure out how to best dive safely in Cozumel with our Suunto computers - and please do not suggest buying new computers is the answer!
Brief background:
Shortly after purchasing my Suunto Cobra, I recall being advised by an instructor in Grand Cayman that it would be fine to incur a deco obligation at depth up to 10 minutes as it would clear during my multi-level profile as I ascended and did my safety stop. I opted not to voluntarily put my new computer into deco on that trip but I was diving in conditions and sites that easily allowed me to modify my depth to be shallower that the rest of the group.
Shortly after that, I switched to diving Nitrox, and I no longer came even close to my NDL times on my repetiitve dives, and so I never had issues with Suunto being too conservative even when we were doing five dives a day (albeit with longer surface intervals than 60 minutes) on any of our subsequent dive trips.
Fast forward to the present:
We will be heading to Cozumel in a couple of weeks and based on what I reviewed from other trip reports, I am concerned that the dive profiles for our two tank boat dives we wil be doing may be problematic for us as we are diving with Suunto computers.
Because of conditions specific to Cozumel (ie. swim throughs at depth and possible strong currents), I am anticipating that the first dive of the day in Cozumel may be at a depth greater than the MOD for EAN 32% so we were planning on diving air. Then we are assuming that there will be a very short 30 minute surface interval before the second dive, so we are planning to dive wither EAN 32% or EAN 36% to help extend our NDL time for this second dive. However, my understanding is that Suuntos really impose serious penalties on the NDL's for surface intervals shorter than 60 minutes.
My questions for Nitrox divers in Cozumel are:
1. Do people commonly dive air on the first tank and then EAN on the second tank in Cozumel? ie. Will using EAN give us a more reasonable NDL on this second dive?
2. Is yes, would you recommend diving EAN 32% or 36% giving the typical second dive profiles in Cozumel?
3. Is anyone aware of oxygen toxicity problems diving with Nitrox on the first deep dive?
My questions for those familiar with Suunto computers are :
1. Would you allow the Suunto computer to go into deco and assume it will clear as you slowly ascend (10 ft/min) with mulitlevel stops for several minutes at 50 and 40 and 30 feet?
2. If yes, what is the maximum deco obligation that you would incur (assuming, of course, that this still falls within the gas plan)?
FWIW, I did do a search on SB forum and found numerous comments condoning this type of practice to counter the overly conservative limits of the algorithm. For example, here is a quote from lamont in another thread:
"Realistically on a Suunto with 5 minutes showing (2 mins mandatory + 3 mins safety stop) you're not in much danger at all. You can probably even go across that by another 5 mins at depth and while the Suunto will probably be telling you 10+ mins of deco to do, you'd be fine blowing it off if the absolute worst case happened to you.
So yes, I realize that I have no technical training, and that I am diving a single AL80 tank, but I am also getting the impression that in the worst case scenario, it is the computer that will get bent, and the dive plan is still within safe recreational limits on pretty much any other computer.
I am hoping to get responses that will help me figure out how to best dive safely in Cozumel with our Suunto computers - and please do not suggest buying new computers is the answer!