Is this a Bad Dive Plan for Cozumel?

[bbarnett51]

I don't think i answered your questions I'm my last post.

Don't assume your computer will clear with multi level stops. If you barely went into a deco obligation then it probably will(mine does sometime) but that's no way to plan a dive.

A deco obligation that simply extend your safety stop is not a buff deal for some. Of course it depends on several factors. Your ability to understand what your computer is telling you, are you in current(very important consideration) if you can't find the line or its a free ascent then you will be missing that boat!, your ability to calculate your air consumption at depth, etc.....

 

[Dr Dog]

you could always put your cobra in gauge mode, and use your tables. But you may not be able to get it out of gauge mode for a time period after your dive

I think you will find COZ ops pretty good. I dove with two sep ops over 5 days, with at least 2 dives per day. Doing the swim throughs and some at depth( 70- 99) and never had any issues. Their SI were all about an hour or more. By the time everyone gets back on board and settled away, 20 mins are gone

 

[ferris213]

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

If bending the computer is your plan, surely that is the best case scenario. Worst case is you in a chamber ,or worse, after deliberately going into deco with no training and no real plan for clearing it other than guessing it gets worked off on your way to the surface.

As I mentioned in the OP, I have been on 2 tank boat dives in Grand Cayman before and questioned the safety of the short surface interval. They were unwilling to extend the surface interval time and suggested diving with the Suunto going into deco as I described (but assuming the ASC time to clear by the time I reached the safety stop)..

This sounds like the problem to me, unrealistically short SI and a dive shop that brushes off your concerns by telling you to just go into deco and hope.

I don't own a Suunto and I'm not experienced with anything beyond rec diving within NDL's, but it doesn't sound like a great idea to me. Is there not time to change your dive op for one that has a more relaxed schedule?

 

[Searcaigh]

I have been using Suunto computers since I got my first computer (Suunto Companion back in the late 90s), before that it was all tables and briefly the PADI Wheel.

Nothing wrong with conservative planing .... safer after all, who wants to end their overseas dive trip in a chamber?

Currently use a Vytec and mainly dive Nitrox, my daughter uses a Zoop and the compare very well when we both dive together.

Never dived Coz though and I would be reluctant to be doing deep dives with only 30 min SI whatever computer I would be using.

Why dive Air then Nitrox, surely best option is to dive Nitrox on both dives if it is available?

 

[gasgirl]

I don't think i answered your questions I'm my last post.

Don't assume your computer will clear with multi level stops. If you barely went into a deco obligation then it probably will(mine does sometime) but that's no way to plan a dive.

A deco obligation that simply extend your safety stop is not a buff deal for some. Of course it depends on several factors. Your ability to understand what your computer is telling you, are you in current(very important consideration) if you can't find the line or its a free ascent then you will be missing that boat!, your ability to calculate your air consumption at depth, etc.....

Yes, that is the question I am asking to those who dive with Suuntos AND have allowed the ASC time to appear: How many minutes beforet actually incurring an extended safety stop?

---------- Post Merged at 09:54 AM ---------- Previous Post was at 09:46 AM ----------

you could always put your cobra in gauge mode, and use your tables. But you may not be able to get it out of gauge mode for a time period after your dive

I actually have a couple of Aeris computers that are Air only that I would be better off using rather than just diving tables with the Cobras in gauge mode. However, that would limit us from using any Nitrox during this trip.

---------- Post Merged at 09:59 AM ---------- Previous Post was at 09:46 AM ----------

I think you will find COZ ops pretty good. I dove with two sep ops over 5 days, with at least 2 dives per day. Doing the swim throughs and some at depth( 70- 99) and never had any issues. Their SI were all about an hour or more. By the time everyone gets back on board and settled away, 20 mins are gone

Here is a quote from a November 2011 trip report from islanddream at the same dive op that I booked in Cozumel:

"Probably the biggest eye-opener for us were our Suunto Cobra computers! We've had them for ten years and they have worked great for the diving we've done previously. During this week we did some fairly deep dives (my max was 116') with swim-throughs, walls, etc. Our past diving history was much more conservative and our computers never put us close to deco. However, because of the profiles we were diving each day, we got very close to deco many times. What a pain to have to ascend when there were so many more swim-throughs to do! Anyhow, Jorge said it perfectly... "those computers are s--t!" And we have to agree because they are SO conservative! Like I said, they've done us well in the past, but we are now diving a much different profile."

 

[DandyDon]

It's interesting when people buy these computers then try to work around them.

You Coz SIs should always be at least an hour. If not, change Ops.

 

[Mike]

I think you have two very big pieces of miss information which are these --

I am anticipating that the first dive of the day in Cozumel may be at a depth greater than the MOD for EAN 32%.

Then we are assuming that there will be a very short 30 minute surface interval before the second dive

And then of course my suggestion is going to be to buy new dive computers. Suntos blow.

Email your dive op and ask them some questions in regard to the typical dive profiles and surface intervals you will be experiencing.

30 minute SI -- never experienced it, would't accept it even if they tried it.

 

[gasgirl]

It's interesting when people buy these computers then try to work around them.

You Coz SIs should always be at least an hour. If not, change Ops.

Well, I do agree with diving conservatively, so I guess that's what the salesperson picked up on and sold me Suunto. I didn't know enough at the time to understand the implications of being unneccesarily conservative and now I can't justify the expense of buying new computers when they work fine for us.

Certainly, when we do our own dive plans when shore diving, we do not push the limits. Of course, we have very little control of the SI when we sign up for a boat dive. Everyone on SB speaks highly of this dive op. We have never been diving in Cozumel and I am just trying to anticipate any challenges we may or may not encounter.

I will email the dive op to ask them about the duration of their surface intervals and see how they respond.

 

[Kilili]

Bad habit to start breaking the rules. Easy to push it too far.

If you're going to use a dive computer, adhere to it. If it accumulates deco time, be prepared to work it off.
Sure, Suuntos are pretty conservative, but needlessly so? I think not. It simply allows for more safety margin.
Deco calculations are not exact science, but rather based on theoretical models that seem to yield pretty safe results.
You might say it comes down to "what odds are you willing to consider for your safety?"

Now, very few divers get bent, despite a multitude of errors committed by some of them. Yet, I have been in Cozumel and seen a very healthy, young, experienced diver get bent on a routine, uneventful dive, despite his dive computer's "guarantee" of safety.

As an aside, have you been screened for PFO, which increases your risk?

Your worst case is you could get bent or die, but happily someone else has a chance to claim a relatively new conservative dive computer.

---------- Post Merged at 11:36 AM ---------- Previous Post was at 11:29 AM ----------

Of course, we have very little control of the SI when we sign up for a boat dive.

You have far more control over your surface intervals that you realise. Before you commit with a dive operation, you explain to them your requirements. If they cannot be respected, you're with the wrong outfit. No one forces you to jump into the water. Remember, it's your safety that's at stake. This overrides whether they'd like to go home a little earlier.

 

[bbarnett51]

I don't think i answered your questions I'm my last post.

Don't assume your computer will clear with multi level stops. If you barely went into a deco obligation then it probably will(mine does sometime) but that's no way to plan a dive.

A deco obligation that simply extend your safety stop is not a buff deal for some. Of course it depends on several factors. Your ability to understand what your computer is telling you, are you in current(very important consideration) if you can't find the line or its a free ascent then you will be missing that boat!, your ability to calculate your air consumption at depth, etc.....

Yes, that is the question I am asking to those who dive with Suuntos AND have allowed the ASC time to appear: How many minutes beforet actually incurring an extended safety stop?

---------- Post Merged at 09:54 AM ---------- Previous Post was at 09:46 AM ----------

you could always put your cobra in gauge mode, and use your tables. But you may not be able to get it out of gauge mode for a time period after your dive

I actually have a couple of Aeris computers that are Air only that I would be better off using rather than just diving tables with the Cobras in gauge mode. However, that would limit us from using any Nitrox during this trip.

---------- Post Merged at 09:59 AM ---------- Previous Post was at 09:46 AM ----------

I think you will find COZ ops pretty good. I dove with two sep ops over 5 days, with at least 2 dives per day. Doing the swim throughs and some at depth( 70- 99) and never had any issues. Their SI were all about an hour or more. By the time everyone gets back on board and settled away, 20 mins are gone

Here is a quote from a November 2011 trip report from islanddream at the same dive op that I booked in Cozumel:

"Probably the biggest eye-opener for us were our Suunto Cobra computers! We've had them for ten years and they have worked great for the diving we've done previously. During this week we did some fairly deep dives (my max was 116') with swim-throughs, walls, etc. Our past diving history was much more conservative and our computers never put us close to deco. However, because of the profiles we were diving each day, we got very close to deco many times. What a pain to have to ascend when there were so many more swim-throughs to do! Anyhow, Jorge said it perfectly... "those computers are s--t!" And we have to agree because they are SO conservative! Like I said, they've done us well in the past, but we are now diving a much

You can't really answer that question. The computer adjusts according to your current profile. So you can't predict when it will clear from a deco obligation. You need to either dive the computer or accept the deco obligation. If u go into it don't panic. It will tell you your ceiling and time but I would just dive the computer and enjoy your dive. Dive nitrox and use 28 if you think you will go over the 32 MOD.