Skirting the Tables

[NSDiver]

By any measure, this is an abuse of the algorithm.

You had 42 minutes of bottom time to play with, used up 40 of it with a dive with a deeper excursion, and then bailed yourself out with a 3 minute safety stop, which may have actually been a required decompression stop if the true profile was considered.

With the uncertainty of the tables, trying this again could result in Type I DCS.

In fact, you may have taken a hit but are in denial about it.

This is the worst idea I have heard in a while.

I didn't 'bail myself out' with the 3 minute safety stop. In all of my dives (though few), I've done a safety stop. I wasn't adding the safety stop because I thought I needed it because of the extra depth- I dove like I only went to 50 feet and did the same SS I've always done.

 

[Whitelightnin]

Your dive was a safe one due to the fact that it was a multilevel dive. However, if you are using tables, you should USE the tables. If I were you, I would break down & buy myself a computer. If you remain an active diver, you will wind up getting one shortly anyway. As you know, computers cut you a custom profile based on that specific dive. No more worrying about square profile dives.

James

 

[PerroneFord]

By any measure, this is an abuse of the algorithm.

You had 42 minutes of bottom time to play with, used up 40 of it with a dive with a deeper excursion, and then bailed yourself out with a 3 minute safety stop, which may have actually been a required decompression stop if the true profile was considered.

With the uncertainty of the tables, trying this again could result in Type I DCS.

In fact, you may have taken a hit but are in denial about it.

This is the worst idea I have heard in a while.

Whoa man., aren't you being a bit harsh here?

He had 42 minutes of BOTTOM TIME to play with. Or have you forgotten tables are bottom time and not run time? He spent considerable time at 30ft (he was already offgassing whether he knew it or not) and was on the 15ft deco at 40 minutes. He actually used LESS bottom time than indicated by the table and stayed under the water for an additional minute over his plan. Any additional on-gassing at 52 feet was more than paid back at 30, because the recreational planners don't credit any deep stop or deco below 15ft.

How the heck is he gonna take a hit swimming around in 30-40ft of water with an AL80 on his back? Heck, I just ran a profile of 90 minutes at 40 feet and Vplanner asked for a 2:36 stop at 10 feet.

The BIGGEST problem here is that he was ignorant to the fact of what he was actually doing, but don't blame the guy for making a logical and well reasoned decision and then coming here and asking about it.

 

[partridge]

Never push the limits. I am sure you were told this in class. Yes it was only a few seconds but what if your depth gauge was off by a few feet also? Then you would have been deeper than 52 feet for a few seconds? Stay well within your plan to avoid situations like these.

And if you do this for 4 dives in one day, you might get hurt. Or if you do it for a bit longer and a bit deeper? and so on. Why use tables at all?

 

[Nomad]

NSDiver - Normally I would keep my opinions to myself, but since you are asking, I'm gonna throw in a few thoughts...

Frankly, it doesn't sound like you have enough experience under your belt to be re-writing dive tables in the middle of your dive.

As Uncle Pug pointed out, the difference between 50 ft and 52 ft is not significant, however, you are establishing habits now. Yes, you can always learn to break bad habits later, but why start out pushing the limits?

Your dive tables establish a fairly conservative baseline, but until you have a much better understanding of decompression theory, you don't know which limits you can safely push.

Remember that while learning to dive, you are also in the process of deciding what kind a diver you are going to be. How conservative/safe will you be?

 

[Don Burke]

I didn't 'bail myself out' with the 3 minute safety stop.

As planned, your dive took you within two minutes of required decompression. You went deeper than the plan. Either that or a little depth gauge error could have put you over the limits. Regardless of what you have done on previous dives, the stop bailed you out and you performed the stop.

One of the most common symptoms of DCS is denial.

Believe whatever you wish.

 

[Skeeter1097]

If you are going to use tables. Don't play games and thinks as it was ok. You well get hurt that way. Or hurt someone else hurt. Get a computer and live by it. Or die by it you choose. You probably didn't hurt yourself but next time you'll stretch it more and that can get you hurt. Don't make this a habbit, you'll only hurt your self in th elong run.

 

[NSDiver]

NSDiver - Normally I would keep my opinions to myself, but since you are asking, I'm gonna throw in a few thoughts...

Frankly, it doesn't sound like you have enough experience under your belt to be re-writing dive tables in the middle of your dive.

As Uncle Pug pointed out, the difference between 50 ft and 52 ft is not significant, however, you are establishing habits now. Yes, you can always learn to break bad habits later, but why start out pushing the limits?

Your dive tables establish a fairly conservative baseline, but until you have a much better understanding of decompression theory, you don't know which limits you can safely push.

Remember that while learning to dive, you are also in the process of deciding what kind a diver you are going to be. How conservative/safe will you be?

I like to think that I'm a conscientious person and diver - and the reason I posted this thread was to incite a discussion about the necessity of ALWAYS staying within your own limits of knowledge and training.

While doing the dive, I knew that I was 'safe' for reasons already stated, but that I wasn't 'being safe' because I deviated from my training and technically messed up.

I'm glad that this thread - while I'm getting some deserved criticism, is helping to reiterate the fact that it's a bad idea to rationalize that you are being safe when you might not be.

 

[lamont]

At 10 dives you need to play it a little conservative. Stay away from the edge of the NDL curve, keep it so that there's a little margin in case you blow off your stop. You will screw up a few times as you learn either through gas management issues, equipment issues or weighting issues and find yourself at the surface ahead of schedule. If you're planning dives with little safety margin that puts you at larger risk.

So on this dive what you did probably wasn't bad, but it could have had a different outcome.

 

[Skeeter1097]

I started doing the same thing because my charts i thought were to safe .So i went out and got a computer i increased my dive times by 25 % but i don't go one minute over the computer. i know what you are saying just be careful!