Dive Check List

jkaterenchuk · 22nd November 2006, 12:35

I like others was trained to utilize a predive check list. Over time while reading contirbution of others on Rebreather World I have expanded this check list. It includes both predive checks as well as those that should be completed during the initial portion of the dive.

ie....checking that cells are not current limited.

I would like to hear from others what they include on their predive/initial dive check list that is beyond the manufacturers standard recommendations? Try to be generic in nature (ie...things that are good to do regardless of type of unit)

If it easier to send me a copy of your checklist let me know and I can supply my email.

I will be happy to post the final list.

**trob09** · 22nd November 2006, 12:54

Quote: (Originally Posted by jkaterenchuk)

I like others was trained to utilize a predive check list. Over time while reading contirbution of others on Rebreather World I have expanded this check list. It includes both predive checks as well as those that should be completed during the initial portion of the dive.

ie....checking that cells are not current limited.

I would like to hear from others what they include on their predive/initial dive check list that is beyond the manufacturers standard recommendations? Try to be generic in nature (ie...things that are good to do regardless of type of unit)

If it easier to send me a copy of your checklist let me know and I can supply my email.

I will be happy to post the final list.

Separate from the manufacturer's list, here's what I do on every dive:
Gas, gauge, lungs, lift, lips, computer, count...

Gas - check O2, Dil & Bailout valves, make sure they are turned on
Gauge - check gauges, confirm available gas supply (O2, Dil & bailout)
Lungs - Check counter-lungs, test O2 & ADV manual add, test ADV isolator, check OPV on exhale lung..set to appropriate positions
Lift - test drysuit inflator and BC inflator
Lips - Check regs (bail-out) and DSV (test open/closed)
Computer - check that it's on & functioning and working it's way toward selected setpoint, compare handset(s) to HUD
Count - 2 minute pre-breathe - watch computer/HUD track setpoint. Watch for any funny feelings during pre-breathe.

The above is done on the bench, fully kitted up before I splash. When I splash, I go through the same again on my way to 20', purging the loop & adding O2 to test cell responsiveness & current limitations. In the water, "count" becomes "current" for checking current limits of cells.

Several others on the list will recognize these as "the 2's" we learned from our instructor, I simply added the gas, gauge...Mnemonic for myself.

There are, of course, numerous checks before I get to this point, largely based on the manufacturer's check-list and recommendations.

dgschott · 22nd November 2006, 20:31

Yup... Know the 'two's' very well.. ;-) However, don't forget the pre - predive two's.... If I have time later tonight I'll post 'em - but I'm in the middle of some work right now! ok - quickly though...

EQUIPMENT CHECK: 3 - TWO'S CHECK LIST.

A. ANALYZE TWO TANKS FOR CONTENT:1 OXYGEN; 2 DILUENT;3 OFF BOARD GAs

B CANISTER & ELECTRONICS: 1 CHECK SCRUBBER, SPACER & ABSORBENT USE & TIME (2 hours), 2 Orings; 2 CHECK O2 SOLENOID CONNECTION, OPERATION & ELECTRONICS

C LEAK TEST COUNTER LUNGS: 1 POSITIVE TEST; 2: NEGATIVE TEST

Sorry - I have it in excel format and it didn't come up right on the post.....

Quote: (Originally Posted by trob09)

Separate from the manufacturer's list, here's what I do on every dive:
Gas, gauge, lungs, lift, lips, computer, count...

Gas - check O2, Dil & Bailout valves, make sure they are turned on
Gauge - check gauges, confirm available gas supply (O2, Dil & bailout)
Lungs - Check counter-lungs, test O2 & ADV manual add, test ADV isolator, check OPV on exhale lung..set to appropriate positions
Lift - test drysuit inflator and BC inflator
Lips - Check regs (bail-out) and DSV (test open/closed)
Computer - check that it's on & functioning and working it's way toward selected setpoint, compare handset(s) to HUD
Count - 2 minute pre-breathe - watch computer/HUD track setpoint. Watch for any funny feelings during pre-breathe.

The above is done on the bench, fully kitted up before I splash. When I splash, I go through the same again on my way to 20', purging the loop & adding O2 to test cell responsiveness & current limitations. In the water, "count" becomes "current" for checking current limits of cells.

Several others on the list will recognize these as "the 2's" we learned from our instructor, I simply added the gas, gauge...Mnemonic for myself.

There are, of course, numerous checks before I get to this point, largely based on the manufacturer's check-list and recommendations.

Gilles · 3rd December 2006, 08:52

The most significant diversion I perform from the manufacturer checklist is pre-dive calibration.

I don't do it.

The reasons are detailed in an essay I have attached in a thread I made titled "Rudimentry sensor mv monitoring" in the Meg forum (sorry no link).

In place, I flush the loop with O2 on the bench, and again at 6m on the way down, and again at 6m on the way out and observe the individual cells.

The result of the last in water 6m loop flush (with O2) determines if I perform a post-dive calibration on the moist cells. The logic herein applied is that it is best to calibrate the cells in the state they are expected to operate in. In the 1 year of experience that I have, (and 6 cells) I observe a change of state after about 30 minutes of exposure to loop circulation (i.e. diving). Hence I do consider pre-dive calibration hazardous!

***ScubaDadMiami*** · 3rd December 2006, 19:10

Quote: (Originally Posted by sabgia)

it is best to calibrate the cells in the state they are expected to operate in.

Interesting! Do you notice that the cells seem to stay much closer in range to each other when you do this (meaning the high and low are pretty close throughout even longer dives)?

Gilles · 4th December 2006, 03:50

Quote: (Originally Posted by ScubaDadMiami)

Interesting! Do you notice that the cells seem to stay much closer in range to each other when you do this (meaning the high and low are pretty close throughout even longer dives)?

I'm unsure what you mean.

Do you mean the dynamic range of each cell, or the difference between the cells? If you mean the former, no.

When disparity between cells occurs (usually after some 10-20 hrs on a single calibration), then it is time to post-dive (i.e. wet) calibrate.

Cells on a wet calibration will have a high bias when dry (i.e. ~0.24 in Air, ~1.05 in O2, and ~1.7 in O2 @6m), resulting in a marginal risk of DCS. I consider this risk a good price to pay for greater confidence against ox-tox.

The ideal (I believe) would be to have occasional pressurized cell checks on the bench (to about 2 ATA), calibrated wet.

***ScubaDadMiami*** · 4th December 2006, 04:42

The reason that I was asking is because I notice that I get an increasing spread between the lowest and highest reading cell as my dive progresses especially in warm water (which is where I mostly dive). This, of course, is after calibrating just prior to the dive. So, I was wondering if following your method results there being less of a spread between the lowest reading cell and the highest at the end of a dive.

Gilles · 4th December 2006, 11:29

Quote: (Originally Posted by ScubaDadMiami)

The reason that I was asking is because I notice that I get an increasing spread between the lowest and highest reading cell as my dive progresses especially in warm water (which is where I mostly dive). This, of course, is after calibrating just prior to the dive. So, I was wondering if following your method results there being less of a spread between the lowest reading cell and the highest at the end of a dive.

What I would expect (if you performed a wet cal), is you would observe a disparity when dry (like I described above), and then about 15-35 minutes on the loop, they will all read more closely (for awhile anyway). Based on the 4.5m end of dive flush, a re-cal is needed after about 10 hrs. Some cells seem more affected by saturated loop gas than others.

Other warm water divers I know observe likewise.

22nd November 2006, 12:35	#1 (permalink)
jkaterenchuk . Current Rebreather/s: Inspiration Classic Megalodon Classic Kiss Other Rebreather/s: Join Date: May 2006 Location: Lititz, PA Posts: 651	Dive Check List I like others was trained to utilize a predive check list. Over time while reading contirbution of others on Rebreather World I have expanded this check list. It includes both predive checks as well as those that should be completed during the initial portion of the dive. ie....checking that cells are not current limited. I would like to hear from others what they include on their predive/initial dive check list that is beyond the manufacturers standard recommendations? Try to be generic in nature (ie...things that are good to do regardless of type of unit) If it easier to send me a copy of your checklist let me know and I can supply my email. I will be happy to post the final list.
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22nd November 2006, 12:54	#2 (permalink)
trob09 . Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Feb 2005 Posts: 686	Re: Dive Check List Quote: (Originally Posted by jkaterenchuk) I like others was trained to utilize a predive check list. Over time while reading contirbution of others on Rebreather World I have expanded this check list. It includes both predive checks as well as those that should be completed during the initial portion of the dive. ie....checking that cells are not current limited. I would like to hear from others what they include on their predive/initial dive check list that is beyond the manufacturers standard recommendations? Try to be generic in nature (ie...things that are good to do regardless of type of unit) If it easier to send me a copy of your checklist let me know and I can supply my email. I will be happy to post the final list. Separate from the manufacturer's list, here's what I do on every dive: Gas, gauge, lungs, lift, lips, computer, count... Gas - check O2, Dil & Bailout valves, make sure they are turned on Gauge - check gauges, confirm available gas supply (O2, Dil & bailout) Lungs - Check counter-lungs, test O2 & ADV manual add, test ADV isolator, check OPV on exhale lung..set to appropriate positions Lift - test drysuit inflator and BC inflator Lips - Check regs (bail-out) and DSV (test open/closed) Computer - check that it's on & functioning and working it's way toward selected setpoint, compare handset(s) to HUD Count - 2 minute pre-breathe - watch computer/HUD track setpoint. Watch for any funny feelings during pre-breathe. The above is done on the bench, fully kitted up before I splash. When I splash, I go through the same again on my way to 20', purging the loop & adding O2 to test cell responsiveness & current limitations. In the water, "count" becomes "current" for checking current limits of cells. Several others on the list will recognize these as "the 2's" we learned from our instructor, I simply added the gas, gauge...Mnemonic for myself. There are, of course, numerous checks before I get to this point, largely based on the manufacturer's check-list and recommendations. Last edited by trob09 : 22nd November 2006 at 12:58.
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22nd November 2006, 20:31	#3 (permalink)
dgschott Liquid Productions, LLC Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Aug 2005 Location: Aston, PA Posts: 115	Re: Dive Check List Yup... Know the 'two's' very well.. ;-) However, don't forget the pre - predive two's.... If I have time later tonight I'll post 'em - but I'm in the middle of some work right now! ok - quickly though... EQUIPMENT CHECK: 3 - TWO'S CHECK LIST. A. ANALYZE TWO TANKS FOR CONTENT:1 OXYGEN; 2 DILUENT;3 OFF BOARD GAs B CANISTER & ELECTRONICS: 1 CHECK SCRUBBER, SPACER & ABSORBENT USE & TIME (2 hours), 2 Orings; 2 CHECK O2 SOLENOID CONNECTION, OPERATION & ELECTRONICS C LEAK TEST COUNTER LUNGS: 1 POSITIVE TEST; 2: NEGATIVE TEST Sorry - I have it in excel format and it didn't come up right on the post..... Quote: (Originally Posted by trob09) Separate from the manufacturer's list, here's what I do on every dive: Gas, gauge, lungs, lift, lips, computer, count... Gas - check O2, Dil & Bailout valves, make sure they are turned on Gauge - check gauges, confirm available gas supply (O2, Dil & bailout) Lungs - Check counter-lungs, test O2 & ADV manual add, test ADV isolator, check OPV on exhale lung..set to appropriate positions Lift - test drysuit inflator and BC inflator Lips - Check regs (bail-out) and DSV (test open/closed) Computer - check that it's on & functioning and working it's way toward selected setpoint, compare handset(s) to HUD Count - 2 minute pre-breathe - watch computer/HUD track setpoint. Watch for any funny feelings during pre-breathe. The above is done on the bench, fully kitted up before I splash. When I splash, I go through the same again on my way to 20', purging the loop & adding O2 to test cell responsiveness & current limitations. In the water, "count" becomes "current" for checking current limits of cells. Several others on the list will recognize these as "the 2's" we learned from our instructor, I simply added the gas, gauge...Mnemonic for myself. There are, of course, numerous checks before I get to this point, largely based on the manufacturer's check-list and recommendations. __________________ David Schott Liquid Productions, LLC Last edited by dgschott : 22nd November 2006 at 20:39.
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3rd December 2006, 08:52	#4 (permalink)
Gilles Worship the feminine Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Den Haag (Netherlands) Posts: 761	Re: Dive Check List The most significant diversion I perform from the manufacturer checklist is pre-dive calibration. I don't do it. The reasons are detailed in an essay I have attached in a thread I made titled "Rudimentry sensor mv monitoring" in the Meg forum (sorry no link). In place, I flush the loop with O2 on the bench, and again at 6m on the way down, and again at 6m on the way out and observe the individual cells. The result of the last in water 6m loop flush (with O2) determines if I perform a post-dive calibration on the moist cells. The logic herein applied is that it is best to calibrate the cells in the state they are expected to operate in. In the 1 year of experience that I have, (and 6 cells) I observe a change of state after about 30 minutes of exposure to loop circulation (i.e. diving). Hence I do consider pre-dive calibration hazardous! __________________ Gilles http://www.dirrebreather.com
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3rd December 2006, 19:10	#5 (permalink)
*ScubaDadMiami* Moderator Current Rebreather/s: Optima Other Rebreather/s: Join Date: Sep 2005 Location: Florida, USA Posts: 1,937	Re: Dive Check List Quote: (Originally Posted by sabgia) it is best to calibrate the cells in the state they are expected to operate in. Interesting! Do you notice that the cells seem to stay much closer in range to each other when you do this (meaning the high and low are pretty close throughout even longer dives)? __________________ Howard Packer IANTD CCR Instructor Miami Beach, Florida CCRDiveTraining.com
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4th December 2006, 03:50	#6 (permalink)
Gilles Worship the feminine Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Den Haag (Netherlands) Posts: 761	Re: Dive Check List Quote: (Originally Posted by ScubaDadMiami) Interesting! Do you notice that the cells seem to stay much closer in range to each other when you do this (meaning the high and low are pretty close throughout even longer dives)? I'm unsure what you mean. Do you mean the dynamic range of each cell, or the difference between the cells? If you mean the former, no. When disparity between cells occurs (usually after some 10-20 hrs on a single calibration), then it is time to post-dive (i.e. wet) calibrate. Cells on a wet calibration will have a high bias when dry (i.e. ~0.24 in Air, ~1.05 in O2, and ~1.7 in O2 @6m), resulting in a marginal risk of DCS. I consider this risk a good price to pay for greater confidence against ox-tox. The ideal (I believe) would be to have occasional pressurized cell checks on the bench (to about 2 ATA), calibrated wet. __________________ Gilles http://www.dirrebreather.com
(Offline)

4th December 2006, 04:42	#7 (permalink)
*ScubaDadMiami* Moderator Current Rebreather/s: Optima Other Rebreather/s: Join Date: Sep 2005 Location: Florida, USA Posts: 1,937	Re: Dive Check List The reason that I was asking is because I notice that I get an increasing spread between the lowest and highest reading cell as my dive progresses especially in warm water (which is where I mostly dive). This, of course, is after calibrating just prior to the dive. So, I was wondering if following your method results there being less of a spread between the lowest reading cell and the highest at the end of a dive. __________________ Howard Packer IANTD CCR Instructor Miami Beach, Florida CCRDiveTraining.com
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4th December 2006, 11:29	#8 (permalink)
Gilles Worship the feminine Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Den Haag (Netherlands) Posts: 761	Re: Dive Check List Quote: (Originally Posted by ScubaDadMiami) The reason that I was asking is because I notice that I get an increasing spread between the lowest and highest reading cell as my dive progresses especially in warm water (which is where I mostly dive). This, of course, is after calibrating just prior to the dive. So, I was wondering if following your method results there being less of a spread between the lowest reading cell and the highest at the end of a dive. What I would expect (if you performed a wet cal), is you would observe a disparity when dry (like I described above), and then about 15-35 minutes on the loop, they will all read more closely (for awhile anyway). Based on the 4.5m end of dive flush, a re-cal is needed after about 10 hrs. Some cells seem more affected by saturated loop gas than others. Other warm water divers I know observe likewise. __________________ Gilles http://www.dirrebreather.com
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