Tell the Truth - Is your brain rotting?

[Ari]

Yes, my brain is rotting. Sorry to say, but it is. It's a combination of old age, certain cehmicals, too much Israeli sun and yes, the Vypor Factor.

Remind me again, how are we related?

Ari

 

[Joe R.]

Actually it is an excellant question and I have to be 'honest' and admit that while I often mean well 'I don't always stay within profile'. I know this without downloading my Cobra which thanks to your question and the remarks given I am going to start doing. I'm sure I'l be shocked into improving my diving. That is the idea. I do have trouble believing 42.11% answered so. But no matter what your tables or computer say. As a wise man once said and to tell the truth "getting the bends is a statistical inevitability". All we can do is lesson the chance.:wiz:

 

[jrtonkin]

Well, hardly the voice of experience speaking here, as I have all of the 2 dives beyond the 5 I did for my OW class (and those were a few years ago; *sigh* the joys of being a broke student), but...

I wasn't taught to do profiling as defined in this thread, merely to plan the dive, and then afterwords to replan any following dives using the actual BT/max-depth.

As for using a computer, I don't own one (nor is it on my list of items to buy first, tables and gauges will do for now), and we didn't use them on my OW either.

On the brain-rot topic, I imagine that relying on a computer is only going to be a problem in the case that you find yourself wanting to change plans mid-dive. Note that that's "change plans", something like "hey, there's more to see here at 60' than we thought, if we spend some extra time here, how does it cut into how much time we have available when we go look at the sights at 40'". I.e. imagine going into simulation-mode partway through a dive; is this possible with a computer? It's certainly possible with a set of tables, but doing so would require that you be familiar and comfortable with them, and that's the sort of thing that comes from practice.

I'm an engineer, so I'm comfortable with both math and physics, Computers are good at grunt-manipulation of data, but I prefer working with tables, to any sort of small computer setup I can imagine. With the tables, I can see when and where I'm picking up large N2 loads, and how changes to depth or time will change those loads. (Or, conversely, where I can extend depth/time and still remain within NDL). I expect it is hard to get that sort of ability out of a small device.

Now I just need to find a set of tables setup for doing multi-level stuff. After all, it'd be a shame to treat a dive where I'm doing bouyancy-control practice (and thus spending 2-minute hovers at a bunch of different levels) as a square profile; especially if I wanted to do both a practice and a sight-seeing dive on the same day/weekend.

Jamie

 

[TwoBitTxn]

So essentially what you do is you use your bottom timer to keep track of how long you have been down. And in your head you keep track of an average depth. Adjusting it basically every five minutes or so. And thru experience you have the NDL's or the deco times memorized and dive using that information. If need be you carry tables with you and use them as a reference when necessary.

Is this right?

Tom

 

[Uncle Pug]

Originally posted by Tom Vyles
Is this right?

Basically...
You are correct - that is what I do...see warning at bottom
I explain the way I use tables in the thread *profiling*...
I started this thread to see if computer users really were aware of their actual *profile* during the dive. The two issues are different. One is about paying attention the other is about how I use the information.

Now I need to add a disclaimer:

{warning... do not attempt to use average depths for figuring your NDL... this method is considered unsafe by almost all scuba training agencies... this method could lead to DCS and death.}

>>>However keeping mental track of your actual *profile* during a dive is not a dangerous practice (IMO) and is very wise (IMO)<<<

Allow your computer to figure NDL for you or use tables and figure your NDL using the TBT & Maximum depth (square profile)

 

[Starfish]

Well I have been off the board for over a week doing above water hiking at 8888 feet in Colorado.
So here is my late $0.02. . .

I do not have a computer.
I do plan my dive.
I check my SPG ever 3 to 4 minutes as well as my dive partners.
I keep track of depth, time, and air consumption.
I do keep a mental image of where we are at all times, particularly since many of my dives have been on DM lead reef dives (SEE BELOW).
I do not dive wrecks or overheads.

Some things to consider:
1. When I was on one of these DM lead reef dives, the DM took us down to 82 feet and then proceeded up to 67 feet over the course of 20 minutes while giving us a tour of the reef. He then decided that he wanted to show us some sights at 80 feet!
Every person in my group of 6 noticed the descent, and we hovered back at the 66-68 feet. We started to bang our tanks to get the DM’s attention. He kept going down! As a group, we went up to 60 feet and hung there as a start on ascent. It took him over 5 minutes to look up to find us hovering there in our ascent!
He dove a computer told us that he didn’t understand what the problem was, as his computer said everything was okay.

2. I use a depth gauge and my watch for ascent. I usually spend more time on my ascent then any other person in my diving group. The computer people are usually the first up.

3. When I was in Cozumel, 3 reports of people at the chambers occurred. All were diving recreational. All had dive computers that indicated they dove within limits.
DCS can happen to anyone regardless of their computer or their conservative use of watch and tables, so please do NOT indicate as someone did earlier that using a computer guards against DCS.

4. While NASA did send men to the Moon using computers, all the calculations were derived by hand.
Computers are great tools, but tools fail.

5. HERE IS THE THING THAT MIGHT MAKE YOU GO HMMMMM:
I had an instructor who relies on computer programs to calculate his TRIMIX. Okay to check his mixes???? No he RELIES on it.
This instructor also is DYSLEXIC and would mix numbers up when he read them from the textbook.

WOULD YOU DIVE WITH HIM?????

Finally, In MY personal opinion, if you can’t follow a recreational dive table using a watch and depth gauge, then you should not be diving (flame away!).

 

[MNScuba]

Computers DO NOT rot your brain... they simply help you do dumb things faster.

 

[Welshman]

As others have said plan the dive using the tables and dive the plan. I have a computer - Suunto Mosquito - but it is a means of checking the plan before the dive and during the dive. It is not a substitute for the plan. Although my diving is all planned as recreational no deco stop diving my Instructor emphasised the importance of the 3 minute stop at 5m for the added safety factor.