Skirting the Tables

[MB]

...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.

I'm glad you asked for reactions! That's a reasonable thing to do, and it shows you are not completely sure about what you did, and you want to learn more. As PF said, you made some logical decisions.

You are wondering about applying rules while in a gray area. How much do we as divers need to live with black or white rules? The problem with living in the gray area is that there is a whole lot more to know than we ever really know. The scenario you described is reasonable... a couple of feet for a couple of seconds... But here's the rub: there is error already built in to tables, gauges, timers, our tissues, etc. A 2 foot "violation" could actually be a 5 foot violation depending on your gauge. And remember that folks DO get hit even when following the tables. And, as some others have already pointed out, you are in the beginning of a dive career that requires exquisite compliance with habits. How wise is it to start bending and pushing before you've developed the habits and knowledge base needed to be a really good diver?

I'm glad you are thinking about this, and re-thinking, and wondering aloud. That's a good sign. It would be an even better sign if you walked away from this thread resolved to develop excellent habits, dive a bit conservatively, and stick with the dive plan. Those divers tend to enjoy safe dives a LONG time! No, don't skip the tables to just buy a computer. If you stretch the tables, you'll stretch the computer. Instead, dive smart, and like you did in this thread, keep thinking about your dive performance and wondering how you'll dive better on your next one.

Cheers!

 

[Don Burke]

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

I think not.

He had 42 minutes of BOTTOM TIME to play with. Or have you forgotten tables are bottom time and not run time?

I have not. Have you forgotten the definition of "bottom time"?

He spent considerable time at 30ft

The message I read said "several minutes" not "considerable time."

(he was already offgassing whether he knew it or not)

in some compartments yes, in some compartments, no.

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.

You do not think that ten dives is a little early to be playing "put-n-take" with nitrogen loading?

How the heck is he gonna take a hit swimming around in 30-40ft of water with an AL80 on his back?

Starting with some loading, making a dive mainly to 45 feet with an excursion beyond 50 feet before getting to 30 feet would help.

Heck, I just ran a profile of 90 minutes at 40 feet and Vplanner asked for a 2:36 stop at 10 feet.

By my PADI RDP, he would have been in group L before this dive started. Try feeding a dive of 60 minutes at 50 feet with a 30 minute SI before this dive into Vplanner.

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.

I disagree with the term "well reasoned" in this context. This was "on the fly" deco, which is something guys like Pug can do, but not a good habit for new divers to get into.

If he wants to run multilevel profiles, a computer or a wheel would be a good start.

 

[Charlie99]

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..

So please educate us as to your definition of bottom time, PerroneFord.

So in your knowledge of tables, are the several minutes at 30ft to be included in the bottom time or not?

How about if he spent most of the dive at 50', then came up to 40' for 10 minutes. Is that bottom time or not?

How about some time at 60' after a 100' dive?

The original poster applied common sense and realized that he could reasonably ignore a short excursion beyond the planned depth. The question is how far it is reasonable to push beyond the formal limits of the table. Before we do that, one should at least understand the intended operation of the table, such as that tables definition of bottom time.

 

[JustinW]

PLAN YOUR DIVE, DIVE YOUR PLAN
You are pushing your tables and that is not OK for dive planning and execution. It doesn't mean you will certainly get bent but doing what you did is going beyond your Tables and beyond your limitations in education. If you want to make multilevel dives then you need to learn how to properly make multilevel dives. You cannot safely do what you did without getting a Darwin Award soon. While Table use with multilevel dives is usually quite conservative, you cannot know how much of a safety margin you have with your level of training. And what Skeeter said is innaccurate, you cannot be too safe.

 

[WaterDawg]

NSDiver,

If you did the same dive w/ a comp youd have a lot of time left.

 

[WaterDawg]

...

 

[lamont]

You cannot safely do what you did without getting a Darwin Award soon.

Can we curb the hyperbole a little bit? He's risking a hit, and most likely it would be joint pain or skin bends or something like that, which is a risk that every single last one of us runs, he's just running a little greater risk. He's like someone who has just taken up weight training and is pushing themself too far too fast. You can die from that as well, but typically you just pull a muscle.

 

[PerroneFord]

Don, no, I have not forgotten what bottom time means. But come on man. I agree with ALL the talk about not getting into bad habits at the outset, and the entire thinking on rationalizing this kind of problem. BUT!

This is a guy who KNEW he messed up, and came here to solicit advice and counseling. Telling he's more than likely taken a hit, and is "in denial" is a bit harsh in my opinion. You and I both know that if he had been on a computer for this dive it would have indicated nothing wrong.

And yes, 10 dives is very early to be playing put-n-take with nitrogen loading.

 

[PerroneFord]

I am not here to give you my definition of bottom time. And to be honest, it's not important. The thread is not about me.

It's about a guy who went over his planned time by a minute and his planned depth by 2 indicated feet. He's been told he's taken a hit and is in denial. He's been told he's starting bad habits, and he's essentially been told to not think for himself. By all accounts, he should have visited the chamber after this dive.

Get real. I'd rather see the guy think his way through a problem than get castrated in the forum for posting a legit post.

We ALL know people who've blown WAY WAY more mandatory deco than this with minor issues only.

No, it won't do to make a habit of playing with the edges of mandatory deco with only a few dives under his belt. But he acknowledged he screwed up, and sought some advice here.

I'm glad none of you guys have ever blown a stop, or run off the edge of the NDL tables. You'd all be dead.

So please educate us as to your definition of bottom time, PerroneFord.

So in your knowledge of tables, are the several minutes at 30ft to be included in the bottom time or not?

 

[WaterDawg]

Perrone, I think you too took a hit and are in denial!!! Of course if you had a comp and let it do everything for you, youd be fine.