Alternative to BSAC tables

[Chef]

Not heard that particular rumour and not sure why they would want to go to the expense, given that most people (after initial training) either dive using computers or cut their own tables using the PC.

[chrisch]

There was some traffic on the BSAC forum a while back when Tom Hennesey broke his silence. I think this lead to some speculation.

From my viewpoint I think the problem is that BSAC (and others too!!) like to have table theory in their more advanced diving programmes. EG to do BSAC 1st Class Diver you do some heavy table theory (driving over mountains and suchlike).

As you say Chef, no-one uses tables after initial training so why bother with all this crap?

However, look at it from the training agencies' point of view. A change of tables has reperercusions for the entire training schedule.

For a club that's a lot of work for what?

Its crazy. I have been taught (and tested on) PADI RDP, PADI wheel, IANTD Air, IANTD Nitox, IANTD Trimix and USN/NOAA. I use either my Suunto or V Planner. Now to dive in France at 3star I will have to "learn" and be tested on the French tables...

Would it not be better just to teach deco theory and let people choose what tables they want?

Chris

[Janos]

Originally Posted by chrisch

Would it not be better just to teach deco theory and let people choose what tables they want?

Blimey! I've a degree in Physics and I find some deco theory hard going at times. Especially RGBM. I can't see that being taught to novices. The maths is just too hard!

The big plus of the current set of tables is that they're easy to use. BSAC '88s are simple. And when you put them side by side and compare them to PADI tables they're not that aggressive either. Remember that BSAC '88s use a slightly different definition of Dive Time which is where I think the confusion has crept in.

Both PADI and BSAC tables are aggressive compared to my computer though.

Personally, I would like to see BSAC reduce the maximum ascent rate and I also think that we should be recommending a 3m safety stop rather than 1m, but that's not really a table thing.

Janos

[chrisch]

Well alright not the whole thing!!! What I was getting at was the basic theory - on-gassing, off-gassing, tissue compartments and so-on. I agree that micro-bubble in-vivo surface tension theory is a bit nerdy and hardly a pre-requisite for a 10M dive with 15min BT.......

Yeah the 88s are easy to use and misunderstood. Both they and the PADI RDP have too fast an ascent rate. But there's the rub - if you know enough to critisise the ascent rate you will doubt the tables. I personally wouldn't use either. The answer for most of us is to buy a 'puter.

Given that is the case WTF is the point of calculating whether Bob Diver can make a dive to 31.2M for 18min after driving over the South Downs in an anti-cyclonic weather pattern with barometric pressure of 980mb?

Would it not be better to ask about up-to-date developments in deco theory and establish that candidates know the basics about RGBM, VPM ZHL8/12/16 and the like?

Chris

[Janos]

To be honest, I think at recreational diving, which algorithm (RGBM, VPM ZHL8/12/16 etc) you use is not going to affect your profile that much. The difference is going to be a couple of minutes (?) on a single+pony dive, which is what the most people are doing.

I think there's a difference between the theory and also algorithms. When I teach the deco lesson a large part of it is theory (and letting off bottles of warm soda water). On gassing and off gassing is in there, and also the idea that tissues have different rates of diffusion. But it's not in depth (and at this stage I'm not sure it should be) and it's one of the things I tell people I'm happy to talk about in the pub. I think it's better to spend a lot of time impressing the need for slow ascents, proper hydration, and long safety stops. Certainly when people are starting out I think the emphasis should be on the more 'practical' side.

But people do need something to plan their dives with before they go out and buy computers. I agree the mountain stuff isn't hugely relevant these days, but do remember that Stoney is a level 2 if the weather is bad.

Janos

[Woz]

Originally Posted by Janos

I agree the mountain stuff isn't hugely relevant these days, but do remember that Stoney is a level 2 if the weather is bad.

Janos

Argh do you have some sort of Vulcan mind-meld? I was going to post the same thing. Crappy day, low pressure, Stoney is 100m above sea level...

[String]

My local pool is about 320m ASL so in lots of weather id need to use a different table for its massive depth of 4m

Useful responses to my initial post though - thanks for that. Things to think about although i still dont really know where to get sensible alternatives (ie buy if not internet).

[chrisch]

Originally Posted by Janos

....But people do need something to plan their dives with before they go out and buy computers. ...

Well here might be a real BSAC - PADI difference?? (Not agencies but $$$$?) I trained with PADI and worked for a 5star centre many years ago. It always amazed me how much money people spent in the course of their OW.

By OW Mod4 most OW students had a computer......

Me? Poor kid... but I too bought my 'puter pretty early on. A dive timer/depth device is (& was) the same price as an entry level computer.

Lets clear some stuff up here. Stoney is not an altitute dive. 300m is the start of altitude diving. My comments about different models is aimed more at AD & 1st class diver, not BSAC SD/PADI RD and even within that at the academic section, not practical training. (BSAC practical skills are good its their weirdo academics that I find hard to swallow). New divers, I agree, need a basic table to use while training. Ascent rates of more than 12m/min are discredited in today's world rendering the BSAC 88s & the PADI RDP unsafe. Yeah read it again - unsafe.....

My point is that all the agencies teach the basics - mask clearing, bouyant lift etc. - and they need to differentiate themselves from the other agencies. They do this by some crappy old tables that no-one uses. PADI's RDP is the first doppler tested recreational planner. Yeah and like nobody uses it...

Modern diving is computer diving. The fact that most divers know nothing about the different deco models is not a good situation. The reason for this is that the training acencies - PADI, BSAC et al - are wedded to some defunct old tables that are NOT SAFE to use. The fact that these tables are still used at advanced levels to "explain" deco theory is utter bullshit and bullshit of the worst kind.

If you cannot explain the way the algorithm works why trust your life to it? The DIR fellows get that right............

Chris