Trimix dive 65m 30min

[Pierre Farrugia]

<font color='#0000FF'>I am doing this thread so maybe we can compare a profile with different deco programs. I am using prodive planner with 10% safetly and 20% microbubble formation. For this dive PpO2 at depth 1.4 and deco 1.6. I also would like to comapre gas choices such as deco gas and maybe even see your deep stops. Max depth 65m and 30min bottom time.


&nbsp;Depth1= &nbsp;40msw: &nbsp; 2mins 32%O2 &nbsp;0%He &nbsp;Run Time= &nbsp;2mins
&nbsp;Depth2= &nbsp;65msw: &nbsp;30mins 19%O2 34%He &nbsp;Run Time= 32mins

&nbsp; DIVE 1 DECOMPRESSION REQUIREMENTS &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp;Stop= &nbsp;45msw: &nbsp; 1mins 19%O2 34%He &nbsp;Run Time= 35mins
&nbsp; &nbsp;Stop= &nbsp;35msw: &nbsp; 1mins 32%O2 &nbsp;0%He &nbsp;Run Time= 37mins
&nbsp; &nbsp;Stop= &nbsp;27msw: &nbsp; 1mins 32%O2 &nbsp;0%He &nbsp;Run Time= 39mins
&nbsp; &nbsp;Stop= &nbsp;24msw: &nbsp; 1mins 32%O2 &nbsp;0%He &nbsp;Run Time= 40mins
&nbsp; &nbsp;Stop= &nbsp;21msw: &nbsp; 1mins 32%O2 &nbsp;0%He &nbsp;Run Time= 41mins
&nbsp; &nbsp;Stop= &nbsp;18msw: &nbsp; 4mins 32%O2 &nbsp;0%He &nbsp;Run Time= 46mins
&nbsp; &nbsp;Stop= &nbsp;15msw: &nbsp; 4mins 60%O2 &nbsp;0%He &nbsp;Run Time= 50mins
&nbsp; &nbsp;Stop= &nbsp;12msw: &nbsp; 7mins 60%O2 &nbsp;0%He &nbsp;Run Time= 57mins
&nbsp; &nbsp;Stop= &nbsp; 9msw: &nbsp;10mins 60%O2 &nbsp;0%He &nbsp;Run Time= 68mins
&nbsp; &nbsp;Stop= &nbsp; 6msw: &nbsp;56mins 60%O2 &nbsp;0%He &nbsp;Run Time=124mins

&nbsp; &nbsp; &nbsp;Total time to surface=93mins &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp;Time to first stop=5mins &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp;CNS exposure: 60%peak, 60%dive end &nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp;CNS exposure= 60% &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp;Max PPO2=1.60bar &nbsp;OTU=159units &nbsp;OTUtotal=159
&nbsp; &nbsp; &nbsp;Dive Start: &nbsp; Day 1 &nbsp; Time 00:00 &nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp;Dive Finish: &nbsp;Day 1 &nbsp; Time 02:04 &nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp;Flight Time: &nbsp;Day 1 &nbsp; Time 11:30
&nbsp; &nbsp; &nbsp;Surface gas=21%O2, &nbsp;0%He
&nbsp; &nbsp; &nbsp;Surface interval= &nbsp; 0mins

[Dominic]

Decoweenie with standard settings (GUE gases &amp; GF 35/80, ZHL16B)

Backgas: 15/55/30
Deco req's:
1@36
1@33
1@30
2@27
2@24
2@21
3@18
4@15
6@12
10@9
35@6

Using deco gases: 21/35/44, 35/25/40, 50%, 100%
Total time to surface = 72
CNS: 117.4
OTU: 154
Run time: 103mins

[Pierre Farrugia]

<font color='#0000FF'>Hello Dominic,

Have I understood right,

1. are you using 15/55 as bottom mix , why use an 80m mix on a 65m dive?

2. are you using 4 deco mixes? 2 trimix and 2 nitrox, is this normal and divable in real life such as cylinders carried and cost? Also on what depths all these deo mixes are used except for the 50% and 100% and what are the benefits? Is it acceptable to use a CNS of 117.4% just to cut deco time?

3. Do you dive DIR, and even if not how you stage all that cylinders?

All above are not a provoking comments but sharing and understanding ideas as maybe I can benefit myself.

Regards

Pierre

[Dominic]

Originally Posted by [b

Quote[/b] ]1. are you using 15/55 as bottom mix , why use an 80m mix on a 65m dive?

Yup - cos that's what DW defaults to for this dive
I didn't put in any personal touches on this one - just plugged in depth and time and asked DW what it thought I should do on it's default settings. I'm not a Mix diver, so there's a limit to how much I can explain it's logic..
However, these were all the standard GUE gases, so I daresay a DIR diver will be along shortly who can tell you why these ones in particular are used

[Pierre Farrugia]

<font color='#0000FF'>Hello,

You are right I didn't add a lot of info, but I would like a profile in which you think you can dive. I didn't try to do the best possible profile with 4 mix deco. As to use that profile you need back gas, 30%, 50% , 100% and air for air brakes. Do you all dive this way or this is good only infront of a comp. as I will always take all gases with me but to use a twinset and 4 deco cylinders is too much considering a 65m deoth range?

Thanks

Pierre

[Mark Chase]

Both Dom and WL have posted profiles with over 100% cns post dive. 114% and 117%. Also they both use multiple stages for travel and deco I note that neither diver is a trimix diver.

Also Doms use of bottom gas is due to the GUE (DIR) philosophy of set gas mix so he has the choice of the folowing gas list:

Bottom Mix

3-30m

In real

THE REST OF THIS THREAD IS MISSING SO I RE DID IT ON THE NEXT PAGE

[Sandman]

Using V-Planner with conservatism set at +4 would give me this. &nbsp;I used to use 50% and O2 for deco but for the dives I do it was adding about another 25% onto the CNS total and only cutting my deco down by a few minutes. &nbsp;I also have a bit more leeway on the 6m stop using 80%.

Dec to &nbsp;60m (4) &nbsp;on &nbsp;Trimix 18.0/40.0, &nbsp; &nbsp;15m/min descent.
Dec to &nbsp;65m (4) &nbsp;on &nbsp;Trimix 18.0/40.0, &nbsp; &nbsp;18m/min descent.
Level &nbsp; &nbsp;65m &nbsp;25:43 (30) &nbsp;on &nbsp;Trimix 18.0/40.0, &nbsp; &nbsp;1.34 &nbsp;ppO2, &nbsp;30m &nbsp;EAD
Asc to &nbsp;48m (31) &nbsp;on &nbsp;Trimix 18.0/40.0, &nbsp; &nbsp;-10m/min ascent.
Stop at &nbsp;48m &nbsp; 0:18 (32) &nbsp;on &nbsp;Trimix 18.0/40.0, &nbsp; &nbsp;1.04 &nbsp;ppO2, &nbsp;21m &nbsp;EAD
Stop at &nbsp;42m &nbsp; 2:00 (34) &nbsp;on &nbsp;Trimix 18.0/40.0, &nbsp; &nbsp;0.93 &nbsp;ppO2, &nbsp;18m &nbsp;EAD
Stop at &nbsp;36m &nbsp; 4:00 (38) &nbsp;on &nbsp;Trimix 18.0/40.0, &nbsp; &nbsp;0.82 &nbsp;ppO2, &nbsp;14m &nbsp;EAD
Stop at &nbsp;30m &nbsp; 3:00 (41) &nbsp;on &nbsp;Trimix 18.0/40.0, &nbsp; &nbsp;0.72 &nbsp;ppO2, &nbsp;11m &nbsp;EAD
Stop at &nbsp;27m &nbsp; 3:00 (44) &nbsp;on &nbsp;Trimix 18.0/40.0, &nbsp; &nbsp;0.66 &nbsp;ppO2, &nbsp;10m &nbsp;EAD
Stop at &nbsp;24m &nbsp; 2:00 (46) &nbsp;on &nbsp;Nitrox 40.0, &nbsp; &nbsp;1.35 &nbsp;ppO2, &nbsp;16m &nbsp;EAD
Stop at &nbsp;21m &nbsp; 3:00 (49) &nbsp;on &nbsp;Nitrox 40.0, &nbsp; &nbsp;1.23 &nbsp;ppO2, &nbsp;14m &nbsp;EAD
Stop at &nbsp;18m &nbsp; 3:00 (52) &nbsp;on &nbsp;Nitrox 40.0, &nbsp; &nbsp;1.11 &nbsp;ppO2, &nbsp;11m &nbsp;EAD
Stop at &nbsp;15m &nbsp; 5:00 (57) &nbsp;on &nbsp;Nitrox 40.0, &nbsp; &nbsp;1.00 &nbsp;ppO2, &nbsp;9m &nbsp;EAD
Stop at &nbsp;12m &nbsp; 7:00 (64) &nbsp;on &nbsp;Nitrox 40.0, &nbsp; &nbsp;0.88 &nbsp;ppO2, &nbsp;7m &nbsp;EAD
Stop at &nbsp;9m &nbsp; 8:00 (72) &nbsp;on &nbsp;Nitrox 80.0, &nbsp; &nbsp;1.51 &nbsp;ppO2, &nbsp;0m &nbsp;EAD
Stop at &nbsp;6m &nbsp; 35:00 (107) &nbsp;on &nbsp;Nitrox 80.0, &nbsp; &nbsp;1.28 &nbsp;ppO2, &nbsp;0m &nbsp;EAD
Asc to &nbsp;sfc. (107) &nbsp;on &nbsp;Nitrox 80.0, &nbsp; &nbsp;-10m/min ascent.

Off gassing starts at 50 m

OTU's this dive: 139
CNS Total: 53.2%

6626.9 ltr &nbsp;Trimix 18.0/40.0
1038.5 ltr &nbsp;Nitrox 40.0
1424.7 ltr &nbsp;Nitrox 80.0
9090.1 ltr &nbsp;TOTAL

Hope this helps

Cheers

Simon &nbsp;

[Pierre Farrugia]

<font color='#0000FF'>Hello,

You are right I wanted to compare prog. I didn't downloaded my self such programs as I want to know if possible from people who uses these prog and compare them with mine. I found Proplanner to be perfect for me and is 100% same as Suunto Vytec, the sort of sfely I need. Maybe Mark speaks from experience as a normal tech dive should be up to 80% of CNS clock and all deco gasses must be carried with you trough the dive as you are never sure to find shot line or if you had to abondon dive. If you read my post on Platti ship :0 there were about six guy bend because they didn't find shot and with it deco gasses.

Thanks

Pierre

[Dominic]

Okay, using the gases 19/34, 32% and 60%, on DW defaults, we get the figures:
1@39
1@36
1@33
1@30
1@27
1@24
1@21
1@18
3@15
4@12
7@9
31@6

CNS: 45.7%
OTU: 115
Run-time: 89mins

That more helpful?

[Mark Chase]

Originally Posted by [b

Quote[/b] (Mark Chase @ Aug. 27 2003,15:38)]Both Dom and WL have posted profiles with over 100% cns post dive. 114% and 117%. Also they both use multiple stages for travel and deco I note that neither diver is a trimix diver.

Also Doms use of bottom gas is due to the GUE (DIR) philosophy of set gas mix so he has the choice of the folowing gas list:

Bottom Mix

3-30m

In real

Whoops, half of my reply is missing so it doesn’t make a lot of sense.

It was supposed to read

Available DIR bottom Mix

3 –30m 32% Nitrox
33 – 45m 21 / 35 Trimix
48 – 60m 18 / 45 Trimix
63 - 75m 15 / 55 Trimix
78 – 121m 10 / 70 Trimix

Available DIR Deco Mix

6m 100% 02
21m 50%   Nitrox
36m 35 /25 Trimix
58m 21 /35 Trimix

DIR divers are not suposed to use any other gas mix than these. This can and does result in high CNS profiles and missed deco for the He

As a result the dive plan is limited to and by the available gas mix. This results in extended deco unless (as WL suggested) you ignore the He in the mix. This is a new thing with DIR and it should be noted that ignoring the He in the deco mix reduces the deco on my profile by 10mins. So according to the dive soft where the DIR diver will have missed 10mins of stops. It is notable that DIR have not had the courage of their conviction to put this new theory into their planning soft where. The Americans are a litigatious bunch and I don’t think GI3’s arguments would stand up to scientific scrutiny at the moment .

The use of 100% for deco in 60m for 30min profiles is also going to push the CNS clock over 100% which is not advised by any other agency. Unfortunately DIR do not allow the use of 80% for deco so there is no option but to push the CNS over 100%

Whilst these arguments have been gone over before I think it is important to highlight them again for people reading these threads who might have a limited background knowledge. It also answers the question as to why Dom’s profile used such a strange choice of back gas.

Also 50 –90 is quite an aggressive profile and does not provide deep stops to alleviate Micro bubble formation. This level of dive is better dived on low GFs fro the deeper part of the deco to provide the deep stops or Pyle stops as they are popularly referred to.

So I  personally would opt for a 20-80GF using the ZHL16B model

Back gas would be 18 / 40 trimix P02 1.35 at 65m
Travel 32% Nitrox
Deco 80% 02



Stops in time and depth

1 @ 42m ascend and switch to 32%Nitrox @ 40m
1 @ 30
1 @ 27
2 @ 24
2 @ 21
3 @ 18
5 @ 15
6 @ 12 Switch to 80% on ascent passing 10m
7 @   9
34@  6

Total run time 96mins
Total deco time 62mins
CNS post dive 52%
OUT 125.24  

The point of noting that WL and Dom don’t do Trimix diving was that they would perhaps not have experience of the problems associated with multiple stage bottles. Anything past two bottles is to be avoided if possible. That said I do use a pony of air attached to my twin set as a bail out to first stop depth. This idea is also used by some of the other deep trimix divers in my circle but the mix is redundant and not part of the deco plan.

5min stops for gas switch is also a bit odd as gas switching takes all of  10seconds. Also an additional 5mins at the first switch depth will add to the on gassing of the Nitrogen in the mix which would have to be planned fro in the deco. Prep in the from of unsheathing the reg and hose checking it is the correct mix and switched on and purging the reg is done on ascent. So it’s just a case of reg out reg in. I usually do this on ascent and switch the mix on the computer on the stop.

I am not having a go at any one. I am just looking at some of the practical considerations when planning deco.

ATB

Mark Chase