Problems for a Kelp diver on a Caribbean dive,rental gear.

[GrumpyOldGuy]

Multiple instances of the same computer isn't a fix either, since a software problem in one, is likely to be replicated in all of them.

The software tools some divers use to plan dive on paper are just as likely to have a software problems as a wrist unit. Considering the added complexity of the code, perhaps even more likely. If you use a 2nd software tool to check the first one, then you are back to you first problem (2 results, which is right?)

I am not arguing with you on the value of a printed plan for deco dives. I just think the value is more in the extra time and effort you invest up front, not the media used. That time and effort simply results in a more complete and customized plan, burned into you brain as well as printed, that is more likely to bring you up safe in the event of problems.

 

[jimmy71]

The software tools some divers use to plan dive on paper are just as likely to have a software problems as a wrist unit. Considering the added complexity of the code, perhaps even more likely. If you use a 2nd software tool to check the first one, then you are back to you first problem (2 results, which is right?)

I am not arguing with you on the value of a printed plan for deco dives. I just think the value is more in the extra time and effort you invest up front, not the media used. That time and effort simply results in a more complete and customized plan, burned into you brain as well as printed, that is more likely to bring you up safe in the event of problems.

Now you want to add memorization of the deco plan into the mix????? I would have to say of all my Kit, My brain has failed me the most...... In fact I think that most accident analyses place most of the blame on at least one failure of that unit at some point......

 

[flots am]

> "Share my buddy's, or use my back gas (lost deco gas is in the dive plan)."

So you have a run schedule for back gas only with you on your dive?

Yes, vPlanner calculates it both ways.

> Lets say you are diving with 50% and 100% deco. You lose your 50%. Your plan is to share your buddies. Plan is for him to to finish/complete each stop and then you on his 50% gas. Are you on gassing on those deeper stops while not on the O2 rich deco? You can safely ignore the possible off gassing. What about your buddy as he waits for you to finish your time at a stop? Do you have an additional run schedule for this?

Sorry, this is too complicated to follow, but the plan is simple: My buddy and I each carry enough back gas and deco gas to handle a failure for either buddy, and have a printed plan for either. We both follow the same plan and stay together.

We both have a printed plan (actually just an extra column on the normal plan) that accounts for lost deco gas, so in some bizzare world where we both lost all our deco gas, we have enough back gas and the necessary information to do the required stops.

> Ok, it was 60 min at 150 dive plan, You do thirty before it is turned. Do you follow your orig run schedule?
How would this not be considered best guess? If you had your laptop and a printer at depth with you, Would you be willing to follow the new run schedule V planner calculated?

You're making this too complicated. First, I won't do an hour @ 150'. Second, if I don't happen to know the NDL (or very close to it), I follow the plan.

> The vast majority of equipment we dive with is hardware and we assume ANY and ALL can/will fail. This is why we have redundancy in all systems that may lead to injury/death. I do not see of this is any different. While I have never had a Knife fail on me, I assume it can/will and consider it a critical system and thus have at least 1 if not multiple backups. I can lose a slate and a run schedule can get damaged. You do have redundancies, but of course you would because it is considered a critical system.

Electronics underwater is a "dancing bear". It's not impressive how well the bear dances, but that it dances at all, so I don't trust it with my life. A failure of the computer on my desk means that I have to go get my laptop, which is much less of an issue than having a computer fail underwater with a virtual overhead.

flots.

 

[jimmy71]

Thanks for sharing flots.

So i just want to clarify, You have 4 run schedules on your slate:
1: for planned depth and time with all deco gasses
2: For planned depth +5 mins with all deco gasses (many people I know make this a +10 feet and +5 min, but it does not matter.)
3: For planned depth and time on back gas only
4: for planned depth +5 mins on back gas only

Am I missing any?

To clarify:
I understand that if you lost your 50%, you would use your buddies. I assume you would not buddy breathe of the 50% reg back and forth every couple breathes, but one person would finish the time at a stop and then you would take 50% and finish your time while they waited on backgas to move to the next level. Then repeat. Is this correct?

Thanks for taking the time to consider my nit picking

I grew up in the age of technology and the internet. I have a lot of faith in computers and technology as I did not experience many of the days when they failed like crazy. This is the same thing I look at with diving. I can not fathom the idea of diving with a J valve. I know many people did it safely and the rational of its use, but holy crap those are scary.
I use my GPS for most of my driving and navigation. Regardless if I think I know where I am going or not. I have become reliant on it. With my knowledge of this, it goes with me on vacation and I have multiple backups in my car. I will admit it is not uncommon that I have 3-4 GPS units in my car at any given time (not all plugged in and in use). At what point do we adopt new technology?
jimmy

 

[flots am]

Thanks for sharing flots.

So i just want to clarify, You have 4 run schedules on your slate:
1: for planned depth and time with all deco gasses
2: For planned depth +5 mins with all deco gasses (many people I know make this a +10 feet and +5 min, but it does not matter.)
3: For planned depth and time on back gas only
4: for planned depth +5 mins on back gas only

Am I missing any?

You have extras and seem to be complicating things again.

There are only two slates (it's a flip-wrist thing).

The one on top has the planned dive, and includes a second column for "lost gas"
The one underneath is the contingency plan for extra time, and also has a column for lost gas.

To clarify:
I understand that if you lost your 50%, you would use your buddies. I assume you would not buddy breathe of the 50% reg back and forth every couple breathes, but one person would finish the time at a stop and then you would take 50% and finish your time while they waited on backgas to move to the next level. Then repeat. Is this correct?

We have no problem buddy breathing. You really can't have one breath the deco mix, and have the other wait on back gas because it screws up the deco plan (one diver ends up with more time on the wrong gas).

Thanks for taking the time to consider my nit picking

It's not nit-picking, but you do seem to take repeated passes at over-thinking things. At least for me, dive plans need to be simple, since as they get more complex, the chances for screwing them up increases dramatically.

I grew up in the age of technology and the internet. I have a lot of faith in computers and technology as I did not experience many of the days when they failed like crazy. This is the same thing I look at with diving. I can not fathom the idea of diving with a J valve. I know many people did it safely and the rational of its use, but holy crap those are scary.

I grew up as part of the generation that created "the age of technology", and if you had any idea how much of the important stuff is chewing gum and scotch tape, you wouldn't trust it with anything that could hurt you either.

I use my GPS for most of my driving and navigation. Regardless if I think I know where I am going or not. I have become reliant on it. With my knowledge of this, it goes with me on vacation and I have multiple backups in my car. I will admit it is not uncommon that I have 3-4 GPS units in my car at any given time (not all plugged in and in use). At what point do we adopt new technology?
jimmy

A bus driver recently followed his GPS right into a bridge, crushed the entire top and front and killed a bunch of people. 4 GPSs wouldn't have helped, because he was "following his computer" and it didn't know about his current special conditions (the bridge). The road was there, but the bridge was too low.

Technology is nice, but unless you're talking extensively tested, mathematically validated embedded systems, on very well known hardware under known environmental conditions, it's nothing I'd stake my life on.

flots.

 

[GrumpyOldGuy]

Now you want to add memorization of the deco plan into the mix????? I would have to say of all my Kit, My brain has failed me the most...... In fact I think that most accident analyses place most of the blame on at least one failure of that unit at some point......

I view it more like an open book test.
In both cases the data is available (on the computer or on your slate) if you take time to look at it and given time you should.
However, if you wrote down the plan, you are more likely to have it floating around in you head and recall it instantly, this makes it less likely to blow the plan by omission.
My plans also contain a lot contingency actions, which I do want to be able to execute immediately without looking them up.

 

[jimmy71]

Thanks flots. So I am correct that you have 4 different run schedules on you. I really do not care how you organize them or keep them or if you have them all condensed into one piece of paper.

I admit that I often have a tendency to over think things. I like to stay a couple steps ahead and have plans for various possibilities. I have also played them out in my head and possible reactions to each. Some may seem far flung and far fetched, but I would have rather thought that they COULD happen then not happen. I do not like surprises. The concept of one problem = one solution taught in the tech books has been one of the hardest things for me to accept. I understand the rational, but it is just not in my nature.

"Technology is nice, but unless you're talking extensively tested, mathematically validated embedded systems, on very well known hardware under known environmental conditions, it's nothing I'd stake my life on."
I would have thought that much of diving and technical diving often fails this test. I agree with you, I just disagree where the line is drawn.

Once again. Thanks for taking the time to answer my questions.

---------- Post added April 20th, 2012 at 03:31 PM ----------

I view it more like an open book test.
In both cases the data is available (on the computer or on your slate) if you take time to look at it and given time you should.
However, if you wrote down the plan, you are more likely to have it floating around in you head and recall it instantly, this makes it less likely to blow the plan by omission.
My plans also contain a lot contingency actions, which I do want to be able to execute immediately without looking them up.

Ah yes. I understand what you mean now. I like the open book test analogy.