I died because of my slate - looking for articles/info on slate abbrev.

[Flightlead]

I "died" yesterday on dive 5 of the DSAT Tec 1 course. Actually I died twice, once because I switched to the wrong gas and second because I omitted 10 minutes of deco. I also killed my teammate because I think he let me persuade him that he was confused, not I.

In reviewing my slate today I became very confused about what I had written/planned. I'm convinced the reason for my deaths are solely attributable to the way I wrote my slate. I'd really like to find some articles or other info on good ways to write up technical dive plans on slates. All I can find when I search is advertisements for slates.

Thanks

 

[DA Aquamaster]

I guess I never saw it as being that difficult, but I guess it is a bit involved.

I put the profile at the top of the page with depth, time and gasses with the depth time, run time and mix listed below:

200' for 25 minutes, 18/50, 32%, 100%

Depth__time__run time__mix
200'____25_____25____18/50
110'____1______28_____32
100'____1______29_____32
90'_____1______30_____32
80'_____1______31_____32
70'_____1______32_____32
60'_____3______35_____32
50'_____2______37_____32
40'_____5______42_____32
30'_____7______49_____32
20'_____8______57____100
10'_____15_____72____100

I will have contingency plans on separate pages of a wrist slate or wet notes with the various contingencies listed in the same way for next deepest depth and time, with either deco gas missing, etc. Keeping it separate helps ensure you do not get confused at the start of or during the deco.

Generally speaking, things like what depth to switch to 32%, 50%, 100% etc should be burned into your memory and gas switching should be second nature when you hit that depth, but double check with the deco schedule and cross check with the MOD marking on the tank, and then follow the hose from to the tank to the second stage with your hand to ensure it connects where you think it connects. And finally, use your buddy to confirm you are on the right gas. I am not sure I'd totally trust my buddy either, but if we disagreed, I'd go back on backgas and triple check everything (and I know the reg bungeed under my chin is backgas even in zero viz) until we figure it out - switching to my back gas may prolong the deco slightly, but it will not cause me to oxtox, which could occur with anything else.

My tanks are marked with 3" reflective numbers with the MOD on the "outside" at the base where the buddy can see it and on the "inside" just below the shoulder where I can easily see it.

My richest O2 reg also has a comfobite mouthpiece on it as the plate that contacts the roof of your mouth ensures it will feel different even in zero viz/total darkness. By default then, if it is not backgas (ie: it is coming from a stage) and if it does not have the comfobite mouthpiece, I know it is the other lower percentage deco gas.

It is important to be sure as switching to the wrong gas at depth is still the number one tech dive killer.

How you record the profile is not as important as practicing with it. Practice putting them on the slate then dive them in your head going through the motions mentally at each stop and at each gas switch. In that regard it is a lot like flying an instrument approach, planning, organization, practice, and situational awareness ensure you have adequate mental resources left to deal with the other distractions that may come along.

 

[JeffG]

once because I switched to the wrong gas

Bad. very bad

second because I omitted 10 minutes of deco.

not good, but may be escapable...then again, maybe not

In reviewing my slate today I became very confused about what I had written/planned. I'm convinced the reason for my deaths are solely attributable to the way I wrote my slate.

On the top, I have the avg depth and bottom time that for the plan.

I just have depths (10 ft increments) from deepstop to the surface with the stop times beside them. a line is drawn between depths where there is a gas switch.

I have these in my wetnotes.

I usually just remember the sequence of stops though. I have yet needed to use my notes on a dive.

 

[battles2a5]

Mine is similar to DA's, just a different format:

Header: 150FSW- 20'

Gas___ Depth_Time__Deco_RT
21/35...150.....20......-......0-20
---------------------------------
50........70......-........2.......22-24
50........40......-........2.......24-26
50........30......-........2.......26-28
---------------------------------
100......20.......-.......10......38-37

I draw a dotted line across at each gas switch. I will use the same format for my contingency plans; 10 min late (Header: 150FSW- 30'), 10 feet too deep (Header: 160FSW- 20'), bail-out plan (half BT), and omitted deco plan. With this format I can clearly delineate BT from deco, can verify deco through the RT, and the table is clearly labeled in the header.

If you are just not writing clearly on your slate, you may want to try to write it out on white duct tape and then place the tape on your slate and cover it w/ clear duct tape.

It sounds like you should add a step to your pre-dive checklist to review the plan w/ your buddy and make sure you have the same plan down and you both know it back to front. This is not a discussion you should have at depth w/ a deco obligation looming overhead. You and your buddy should also be confirming gas switches, on your marked deco cylinders . Breathing the wrong gas at depth is probably #1 on the list of tech dive killers.

 

[Flightlead]

thanks all. I'm looking for better ways of recording the data. for example, other than for hangs, air breaks etc, do I need elapsed time or only run time?

da_aquamaster - that is exactly the layout I had on my slate. however we got off on the runtime and that is what threw me. adding to the problem was that at the first stop both gasses were within MOD - which may only happen on a training dive. I did a proper NO TOX switch, however to the wrong mix. I had too much info! I've seen other slates that omit some info, and encode other info as symbols - e.g. a horizontal line as a gas switch etc. my tanks are marked left, right, bottom and both side of the top, that wasn't the issue.

 

[SparticleBrane]

How were you taught to handle, carry, and switch deco mixes?

 

[rhlee]

have never needed to write anything down, yet.... I find that most of the profiles I do are fairly similar, and just remember a schedule for 20, 25, and 30 minutes of deco.

 

[Rainer]

I did a proper NO TOX switch

Does the DSAT/PADI procedure not involve you and your team actually verifying the gas to which you are switching?

I've got to say, having two bottles from "tech day one" strikes me as silly for precisely these reasons. You were clearly quite task loaded (it's a class, part of that is totally understandable). Adding a second bottle just seems like adding a second bullet to the barrel in a game of Russian roulette. If you're having problems reading the deco notes still (and any reason you aren't also memorizing the schedule?), wouldn't you feel more confident with only one bottle?

 

[pickens_46929]

Does the DSAT/PADI procedure not involve you and your team actually verifying the gas to which you are switching?

I've got to say, having two bottles from "tech day one" strikes me as silly for precisely these reasons. You were clearly quite task loaded (it's a class, part of that is totally understandable). Adding a second bottle just seems like adding a second bullet to the barrel in a game of Russian roulette. If you're having problems reading the deco notes still (and any reason you aren't also memorizing the schedule?), wouldn't you feel more confident with only one bottle?

I'll agree with this two bottles day one plus all the new stuff seems like too much overload.

Deco plus contingency get written in wet notes or laminated and carried. Use something very similar to above with Runtime (RT) only. For gas switches you slow down and prepare generally the stop before the gas switch... check gas, double check with buddy, proceed to next stop and switch. No pressure because you're already doing a stop on the right gas.

Task loaded? Load shed... plain and simple.

My tech instructor threw several "broken table" exercises at us during our training. On one of them my buddy and I looked at him telling us we "broke table by 1 min"... we looked at each other, shrugged, pointed to our "planned table" said "yes" and went ahead and did our "planned" table even though we "broke" it by 1 minute.

On the surface, the instructor asked if we got his "broken table" signal, we said yes and that for 1 minute we decided *together* it just wasn't worth the extra deco. He said that's all he wanted to know and for us to do... communicate, agree, execute and know *why* we did what we did.

Now one of the other ones didn't go so well... lol

 

[rhlee]

I've got to say, having two bottles from "tech day one" strikes me as silly for precisely these reasons. You were clearly quite task loaded (it's a class, part of that is totally understandable). Adding a second bottle just seems like adding a second bullet to the barrel in a game of Russian roulette. If you're having problems reading the deco notes still (and any reason you aren't also memorizing the schedule?), wouldn't you feel more confident with only one bottle?

I don't want to turn this into a religious argument, but...

To play devil's advocate for a second, I have heard of way way too many stories of GUE-trained divers switching, or attempting to switch to the wrong gas. Enough to make me wonder if the way we do it (T1 == 1 deco gas, T2 == 2 or more) is making people who do alot of diving at the T1 level get complacent about their switching protocols. To a degree that maybe if they had more than one bottle since day one (or, relatively early on) they wouldn't develop the complacency....