What GF and Ascent rate ?

[Mark Powell]

Get a computer, get deco software and play around to understand the relationships and rules. That's the best way to learn about deco.

Computers and deco software are the lazy way out and you learn nothing from them.

Get a copy of Workman's calculations for M-Values and add in some gradient factor calculations and play around to understand the relationships and rules. Ideally you should use mental arithmetic and not rely on an electronic calculator for the calculations. That's the best way to learn about deco.

[Mark Powell]

More seriously Paul I would look at the behaviour factors rather than getting caught up on specifics of one deco model rather than another.

You have already covered hydration and fitness, two key points. I would agree with the others that slowing up the ascent would help. Certainly from the first stop onwards slow my ascent right down and 1m/min for the last 6m is definitely helpful. In addition if you know you are feeling this way then an extra 5 mins added ont your last stop might also help. There is no prize for being first out of the water.

[Mark Chase]

Seriously Mark, there is no way I'd waste my money on a dive computer without first having a lobotomy!

I don't personally know a single person who's been happy with the VR3 they've owned, but my issue more generally is with dive computers.

They're the lazy way out and you learn nothing from them. Get a computer, get deco software and play around to understand the relationships and rules. That's the best way to learn about deco.



K.

I was perfectly happy with my VR3's and I only changed to the Shearwater after buying a HH CCR that came with GF deco. The VR3 was so different in deco profile it was rendered useless as a back up unless i wanted to do every dive o 20/80 (APX VR3 on 0 Safety)

When i switched from tables to a VR3 it was like someone had removed the shackles and I was now free to enjoy my diving. No more was i tied to run times and depths I was no free to do what the hell i liked and just go up when i had reached the max deco i had the gas for or on CCR had planned for.


Dive plans went from complex multi level dives to a simple How much deco shall i do today?


We didn't have access to ratio deco in 2000 -2004 when i started. It was rumored in dark corners but I for one had no idea how it worked till I basically made up my own. It staid that way till some kind sole sent me a copy of the GUE training manual for Tec1 and shortly after AG published it on the web.


Had it been openly available when i dived OC, Id have used it in preference to the ball and chain tables.


That said tables taught me a lot about deco.

The VR3 also taught me a a thing or to.

I used to dive tables with depth an stop times. When I switched to the VR3 I soon discovered i was ascending too slow. The VR3 was racking up deco on my ascent and it became apparent unless I speed-ed up my ascent significantly it was going to penalize me on the shallow stops.

I wondered just how aggressive i had been on the shallow stops on tables and it made me realize the best way to run deco was stop time,depth AND run time.

When i tracked the VR3 during a dive i got instant feed back on what i was doing and how it altered the plan.

Very educational.


My Shearwater today teaches me how soft and how aggressive Ratio deco is. I use ratio deco on every dive and my computer gives me a 10/90GF comparison base line for the ratio plans.

Its been a very interesting exercise.

[pdh]

OK, here's a profile from my Suunto



Trimix 20/30, 50% and 100% deco gas. Stops look a bit deep as the VR3 and Suunto don't match and I was using the VR3 depths. Should be 21, 6 and 4.5. Mark was right about ascents - not quite as fast as they were planned. Dots are fast ascent warnings so it was close to 10m/min in places. A few minutes extra on O2 at the end. Not perfect, I'll admit. Felt rough several hours later/next day - back and shoulder pains (both shoulders) chamber treatment didn't fix it, but got better after ibuprofen for a week or so.

Paul.

[johnkendall]

OK, here's a profile from my Suunto



Trimix 20/30, 50% and 100% deco gas. Stops look a bit deep as the VR3 and Suunto don't match and I was using the VR3 depths. Should be 21, 6 and 4.5. Mark was right about ascents - not quite as fast as they were planned. Dots are fast ascent warnings so it was close to 10m/min in places. A few minutes extra on O2 at the end. Not perfect, I'll admit. Felt rough several hours later/next day - back and shoulder pains (both shoulders) chamber treatment didn't fix it, but got better after ibuprofen for a week or so.

Paul.

Personally I'd add a bit more time in between 21 and 9. Looks a bit quick in that area.

HTH

John

[pdh]

Computers and deco software are the lazy way out and you learn nothing from them.

Get a copy of Workman's calculations for M-Values and add in some gradient factor calculations and play around to understand the relationships and rules. Ideally you should use mental arithmetic and not rely on an electronic calculator for the calculations. That's the best way to learn about deco.

I appreciate the feedback Mark but my mental arithmetic at depth is pretty crap and to be honest I'm not 'on the leading edge' of deep diving. I just want to be able to do some reasonably deep dives and come back alive. The people that write the software and build the computers are much better at it than me so I'm happy to follow (to a reasonable extent) what they say. My problem is if things don't work as they should I'm not totally sure why or what to do about it. But I'm not sure I'd be any wiser reading about the theory. I'd much rather talk to people like you lot and ask what works for you and try it. So far the feedback I'm getting is slow everything down from about half way and the add some more time at 6m with a very slow ascent to the surface. (and drink more beer )

I'll read what you linked but I've read a lot of Erik Bakers stuff already and I'm still here asking dumb questions.

Paul.

[JasonP]

Personally I'd add a bit more time in between 21 and 9. Looks a bit quick in that area.

I'd personally do a minute stop at every 3m after the first stop. That said, even using 50% deco gas only, I'd have been out of the water a couple of minutes earlier than that profile.

Jason

[Garf]

Im with John that the intermediate stops look, well, non existent. It doesnt look like there was a pause between 21 and 6?

[MattS]

Felt rough several hours later/next day - back and shoulder pains (both shoulders) chamber treatment didn't fix it, but got better after ibuprofen for a week or so.

Pain slow to develop. Does not respond to re-compression. Responds to Ibuprofen and takes a week to clear up...Have you considered it was likely a muscular strain and has nothing to do with DCI?

[Mark Powell]

I appreciate the feedback Mark but my mental arithmetic at depth is pretty crap and to be honest I'm not 'on the leading edge' of deep diving. I just want to be able to do some reasonably deep dives and come back alive. The people that write the software and build the computers are much better at it than me so I'm happy to follow (to a reasonable extent) what they say. My problem is if things don't work as they should I'm not totally sure why or what to do about it. But I'm not sure I'd be any wiser reading about the theory. I'd much rather talk to people like you lot and ask what works for you and try it. So far the feedback I'm getting is slow everything down from about half way and the add some more time at 6m with a very slow ascent to the surface. (and drink more beer )

I'll read what you linked but I've read a lot of Erik Bakers stuff already and I'm still here asking dumb questions.

Paul.

Sorry Paul, that post was meant as a joke in response to Ken's comment. The next post was where I was being serious.