Dive Timer with Multiple Alarms

[alunharford]

Originally Posted by johnkendall

I'm sorry Alun, I'd tried to stay out of this one, but having returned from my Dive trip to read this rubbish has prompted me into action.

I'm not convinced that you can send up a blob properly 75% of the time when you can see. You certainly didn't have the bouyancy control last time I saw you in the water to hold a stop to within 0.5m even with sight and a blob. Maybe you should think about actually finishing Sports Diver before you start trying to post about subjects that you have so little idea about that it is funny.

I take it you didn't bother to actually *read* my posts then?

IIRC This is a problem you've had in the past, and it's really starting to get on my nerves.

I was *TRYING* to get an answer to why *NOT* to do it (rarther than argumentum ad logicam, which is all I've been given up to now) by playing Devil's advocate.

Originally Posted by alunharford

I'm trying to get information by playing devil's advocate and it isn't working

Personally, I think I made that pretty clear in my posts.

I failed and gave up. I didn't care enough about it to carry on asking why people were against it instead of saying "(shrug) who cares? It won't help you so it makes no difference"

Originally Posted by johnkendall

The internet is a funny place, you can make up all kinds of personas for yourself, but you get bitten when people know the real you.

As you must have figured out by now, I'm just as happy to do this in the pub.

Originally Posted by johnkendall

Grow up

<removed>

Originally Posted by johnkendall

(For those of you who don't know, I'm the DO of Alun's club)

That's something I'll have to think about.

[And]

Hi Alun

Ah, the joys of internet forums and BSAC membership.

Firstly, my advice is perhaps not to play devils advocate at your level, as it just winds people up, as IME the devil doesn't do much diving and so is kind of illogical. Its a bit like when kids play the 'why?' game. Ask the questions you want to ask, read the responses, and maybe try it out if its within your training level and experience.

Secondly, I do think John is out of order, and I too would question remaining a member of a club with a DO who would slag off one of his members in front of over 1500 YD members and god knows how many guests for no constructive reason at all. He should have been supportive and PM'd you IMO. As Bren sometimes says he needs to have a word with himself. Perhaps it would be better to update your profile with your experience and training and then other divers will know the context in which you are asking the question and then these attacks on one's character might not happen.

I admit sometimes the 'you'll know why when you get there' answer is a little frustrating but throughout my diving that has usually been the case, and I have gone back a few months later thinking 'why the f**k did I post that??' so my advice which you can take or leave of course, would be to look at the divers doing the type of diving you want to do successfully, and imitate what they do, or ask questions of them or even better, both.

Hope that helps

Andy

[iainmsmith]

> Secondly, I do think John is out of order, and I too would question
> remaining a member of a club with a DO who would slag off one of his
> members in front of over 1500 YD members and god knows how many
> guests for no constructive reason at all. He should have been supportive
> and PM'd you IMO.

As I've know John for longer than anyone else here, I will admit to being a little surprised by his response. I myself probably have something of an (earned) reputation for tearing people to pieces for what I perceive as stupidity, but I wouldn't have anticipated John reopening a thread that had been dead for a couple of days in the way that he did. IMO, it was rather out of character, possibly due to being tired having been driving back from Scotland for many hours. Those who know him from other fora will, I hope, recognise the varience from normal.

However, I still haven't worked out what Alun was trying to ask, despite having read the thread several times over. It appears to me that all his questions were answered and all his points dealt with, publically and privately, with varying levels of politeness.

Originally Posted by alunharford

I was *TRYING* to get an answer to why *NOT* to do it.

IMO, that was answered more than once. I _know_ that I gave at least one answer in private correspondance. To quote from my email:

How many computers do you know that have different alarm sounds? The Suunto Vyper, for example, has at least six different alarm states. It's a single mix computer! AFAIK, all of its alarms sound the same. To even be potentially useful in the situation you imagine (about the difficulties of which you have, by the way, demonstrably no concept) you would have to have separate alarm sounds for every single alarm state, which will increase exponentially in number with the complexity of the computer. Do you think you have a hope in hell of memorising them all? How often are you going to practice with them? You'll end up spending all your time in a swimming pool trying to memorise the morse-code of your computer!

(This was part of the post I removed from the thread)

Not having studied dead languages at school, I almost misunderstood the objection in Alun's last post - he seemed to be complaining about logical arguments - however, in less pretentious terms, "attacking the logic" is surely at the core of discussion of technical diving. If something is, as Spock would have put it, "not logical", why would we do it? It is, IMO, not logical to construct contrived scenarios which require impossible skill levels in order to allow one to make use of an extra "feature" which itself introduces ridiculous complexity, especially when the constructor of the scenario has no idea what he or she is talking about, has had this explained to them, yet still maintains that he or she is right.

Anyway, this thread is rapidly degenerating towards "argumentum ad hominem" (attack on the individual) aimed at various people, so probably ought to be drawn to a close.

Alun,

If you want to talk about technical diving, you're welcome to do so, but please understand that you don't necessarily have the experience to understand why particular things are so. We can try to explain, but at the end of the day: "You can't learn to dive on the net (or in conversation) Ultimately, you have to go out and get wet."

If I knew when I was next going to be able to get wet, I'd be more than happy help you do so. Unfortunately my new job isn't ideal for weekends off...

Iain

[johnkendall]

Originally Posted by alunharford

I take it you didn't bother to actually *read* my posts then?

Actually I Did.

I was *TRYING* to get an answer to why *NOT* to do it (rarther than argumentum ad logicam, which is all I've been given up to now) by playing Devil's advocate.

You did get an answer. It was "It's not needed". It is a very simple answer. One day, if you decide to take your diving in the direction of long stop times, accelerated deco and mixed gasses then you will realise this. Until then you may just have to take the word of others.

That's something I'll have to think about.

That is up to you. I accept that maybe I should have thought about it more before posting what I did, but I haven't removed the post, and I believe that sometimes things like this need to be said.

As Andy has said, the Devil does not make a good diving buddy. If you don't get enough info in answers to your questions, ask more questions, don't try and create scenarios as you have in this thread. By asking questions, you appear to want to know more, by creating scenarios based on wrong assumptions, you just appear to be foolish.

John

[alunharford]

Originally Posted by johnkendall

You did get an answer. It was "It's not needed".

Perhaps I've misunderstood people, but from what I've read, the general view is that it would be 'wrong' to have such a feature. That's not the same as saying it's not needed.

[johnkendall]

Originally Posted by alunharford

Perhaps I've misunderstood people, but from what I've read, the general view is that it would be 'wrong' to have such a feature. That's not the same as saying it's not needed.

At this level of diving "Not Needed = Wrong"

HTH
John

[Tim Ingmire]

Just to be clear then.

Its not needed.

If you need it, you shouldn't be doing it.

If you don't need it, why have it?

[Mark Chase]

Originally Posted by alunharford

Perhaps I've misunderstood people, but from what I've read, the general view is that it would be 'wrong' to have such a feature. That's not the same as saying it's not needed.

There are two distinct camps on computers. Perhaps a good example on warning bleeps is in the CCR camp. The Inspiration has warning bleeps for violations and the KISS doesn’t. The argument goes a warning bleep is better than none. The counter argument is if your monitoring your computers you doesn’t need bleeps and if your not monitoring your computers, why not?

Personally I don’t see anything wrong with warning bleeps but in the context your discussing they would just be an irritation. The computer screen flashes on a multi-mix computer to remind you to confirm the gas switch on the computer and that’s more than adequate for me. At the point when you so complacent that you no longer monitor your computers on deco, your probably an accident waiting for a venue and a bleeper is unlikely to be enough to save you.

ATB

Mark Chase

[iainmsmith]

Originally Posted by alunharford

Perhaps I've misunderstood people, but from what I've read, the general view is that it would be 'wrong' to have such a feature. That's not the same as saying it's not needed.

IMO, less "wrong" and more "pointless". For the "feature" to be of use, we had to put together a ludicrous scenario and assume an impossible level of skill, with the inherent complications outlined. The "feature" has no useful purpose and compromises other, potentially useful alarms (though, if I recall, the item that didn't make the "Bakers Dozen on why not to dive computers" but probably should have done was, "They beep"!)

To the Scot in me, this "pointlessness" makes it "wrong" on the basis that any manufacturer including such a feature would charge a premium for it...money better spent either going diving or useful equipment.

That's aside from John's succint, "Not Needed = Wrong", which is a generally accurate statement, but one which may not intuitively make sense to those unfamiliar with this type of diving. The reason for it is that if something is not needed, including it inevitably introduces some other complication not forseen.

Iain

[And]

Hi Alun

Right, I am assuming that you are still talking about an alarm on a dive computer to remind you to switch.

Wrong or unneeded or unneccessary, all have the same meaning here.

Gas switches are depth related and have nothing to do with time. You cannot run a dive by getting to the bottom at a specific time, diving for a specific time, ascending at a specific time at a specific rate and arriving at the gas switch at a specific time. I am sure you can see why not. You might have problems descending, you might use more gas and ascend early, you might ascend slightly slower. 'catching up' a runtime if I am a little late is translated as missing stops which of course is just not done. These are deco dives and missing stops by catching up a perceived time limit will get you bent.

An example is using 50% nitrox as a deco gas. I switch at 21 mtrs, not 20 mtrs, not 23 mtrs, and definitely not at 42 minutes, its 21 mtrs. I don't care how long I've been diving or whether I have a runtime plan which I am now outside, I will switch at 21 mtrs, and then I start timing my deco as I move up the water column. Whilst ascending I am constantly monitoring my instruments in relation the rate of ascent I have chosen for the dive, I do not need an alarm to remind me to look at them, because quite frankly, that is probably the most important thing in my life at that point, it can be literally a life and death decision.

Thats it, thats the explanation. Time is largely irrelevant when it comes to gas switching, and therefore a 'reminder' is also irrelevant. It has nothing to do with computers per se, it is purely the techniques of accelerated deco diving. If we breathe a gas too deep we tox and die, if we switch a gas too shallow we reduce the effectiveness of deco and get bent. Forgetting is inconceivable, it is like forgetting to press your inflator to alter buoyancy. It is that simple. Like I said before you will know when you get there. At this level of diving the ascent is probably the most practiced, most talked about, most thought of, part of the dive.

Andy