mCCR and zero viz exit

gtzavelas · 1st April 2008, 08:17

Here is a neat trick to solve this problem
Unfortunately I don’t recall who told me so to pass the credit.

Take a small transparent plastic bag (the one used to store food – ziplock type).
Fill in the bag with clear water at the start of the dive and tie it up (put around a bit more than cup of water)
Put the back in your dry suit pocket
When you enter complete silt out zone take bag out of pocket and:
Stick it in front of your mask and then stick your computer/handset in front of the bag and squeeze so the bag is squeezed between the mask and the handset
If the computer/handset has a light then it will be perfectly visible

I have tried and it works!

nskdrs · 1st April 2008, 08:40

Another possible solution:

A tube with a diameter matching ones displaysizes,
kinda works like a telescope ( planparallel "lenses" ),
5cm tube with flat and clear lids to be pressed like a tunnel onto gauges, displays and computers in "zerozero" viz, needs possibility to spill light inside the tube to be compatible with no-backlight-displays.

Friend of mine carries one like this on his "wreckdigger" dives,
he's into solodigging inside wrecks so extensively familiar with diving "thick blackwater",
he does not use a HUD.

Shortsighted divers diving without correction in their masks might need a more sophisticated version with some kind of lenses.

Wouldn't it make a nice accessory to be produced by some thirdparty-manufactor...

...at least maybe nice for backing up a HUD on m/eCCR...

HTH,
Hoffi

Mdemon · 1st April 2008, 11:02

We've used gin bottles in the same way. I like the idea of plastic bags though.

Ironic, given the title of the thread, that the HUD which does give deco info is slapped on a very expensive eCCR, namely the Boris. Or you could wait until the X1 gets its 4th cell add-on. Then you'd have depth, direction(compass), PO2, deco ceiling all in one place. I did toy with the idea of mounting mine on my BOV, but I reckoned tapping it would be tricky...

An OLED screen helps significantly with murk. Perhaps OLED screens for your handsets might help? They're dirt cheap, no pun intended.

silent running · 1st April 2008, 18:14

Quote: (Originally Posted by Gill Envy)

After watching a solenoid stop working mid dive and then start working spontaniously (and that was after a trip back to the hatchery) I've come to the conclusion that eCCR's need an even shorter monitoring interval than mCCR's as you have no MFO and even less time to react to a failing set point controller and no obvious way of calculating the timing of a failure.

Hi Gill, IMHO, stating that you need shorter monitoring intervals with an ECCR is alarmist, as with a HUD you will know if your solenoid stops working as the HUD will show you are below SP. This is what happened to me when mine stopped working. But I knew even before my HUD told me because I could hear the solenoid blocking up.

Call me lazy, but during a period of high stress/work I'd rather not have to remember to push a button, count to 120 or check to see if my loop volume has decreased. I'd much rather use all available brain power and both my hands to try and find a line or my buddy's leg during a silt out...

**sfldiver** · 1st April 2008, 18:46

Quote: (Originally Posted by silent running)

Hi Gill, IMHO, stating that you need shorter monitoring intervals with an ECCR is alarmist, as with a HUD you will know if your solenoid stops working as the HUD will show you are below SP. This is what happened to me when mine stopped working. But I knew even before my HUD told me because I could hear the solenoid blocking up.

I absolutely agree that we should have a short monitoring interval when using a eccr. Whether you use your Handset or your HUD, makes no difference to me, just monitor your PO2 frequently when relying on electronics.

As I posted on a different thread, I did recently have an incident where my handset completely shut down during a dive. I was diving in very calm conditions and was on my knees in 70 ft of depth at the edge of a wreck taking pictures. I generally do not glance at my HUD very often (I probably should), instead I tend to check my primary handset and 4th cell VR3 fairly regularly - Allows me to monitor NDC and Deco Obligation at the same time as my PO2. When I glanced at my primary handset, it was dead. I glanced at my VR3 and my HUD and noticed my PO2 had already dropped below 1.0, from the 1.2 I had the electronics set at. I manually maintained O2 and called the dive...

I now make a conscious effort to monitor my PO2 much more frequently then I previously did, even though I feel as though I was monitoring it at an adequate frequency before!

silent running · 1st April 2008, 19:25

Quote: (Originally Posted by sfldiver)

I absolutely agree that we should have a short monitoring interval when using a eccr. Whether you use your Handset or your HUD, makes no difference to me, just monitor your PO2 frequently when relying on electronics.

As I posted on a different thread, I did recently have an incident where my handset completely shut down during a dive. I was diving in very calm conditions and was on my knees in 70 ft of depth at the edge of a wreck taking pictures. I generally do not glance at my HUD very often (I probably should), instead I tend to check my primary handset and 4th cell VR3 fairly regularly - Allows me to monitor NDC and Deco Obligation at the same time as my PO2. When I glanced at my primary handset, it was dead. I glanced at my VR3 and my HUD and noticed my PO2 had already dropped below 1.0, from the 1.2 I had the electronics set at. I manually maintained O2 and called the dive...

I now make a conscious effort to monitor my PO2 much more frequently then I previously did, even though I feel as though I was monitoring it at an adequate frequency before!

Hello sfld, I'm not sure I understand-your primary handset also controls the solenoid firing? And if so, why isn't the HUD programed to tell you that one of your handsets has stopped working or at least blink/vibrate to tell you that your PO2 is below SP or falling?

And why don't you look at your HUD? Do you have it mounted somewhere other than the DSV? -Andy

**sfldiver** · 1st April 2008, 19:54

Quote: (Originally Posted by silent running)

Hello sfld, I'm not sure I understand-your primary handset also controls the solenoid firing? And if so, why isn't the HUD programed to tell you that one of your handsets has stopped working or at least blink/vibrate to tell you that your PO2 is below SP or falling?

And why don't you look at your HUD? Do you have it mounted somewhere other than the DSV? -Andy

Yep, the primary handset controls the selenoid firing, so when it goes out, your PO2 drops.

The HUD will not not notify me if the primary handset shuts down, because the HUD is controlled by the secondary for redundancy purposes and will continue to blink the current PO2. However, should the PO2 drop or rise to critical levels, heavy vibration will immediately alert me to a problem, and the selenoid will ultimately fire automatically if the PO2 gets too low.

That's my understanding of the system.

I do not generally look at my HUD, because when I took my class, I had lots of difficultly adjusting the HUD to a point where I could clearly see it, so during training, I got in the habit of monitoring my handsets and not the HUD. Since then, I've continued the habit, which is probably something I need to work on. However, keep in mind, I also have the habit of constantly monitoring my handsets, which comes from my deep diving tech days, because I always wanted to know what my deco obligation was climbing to, so now I just monitor my PO2 and check my deco via the handsets frequently.

Mdemon · 1st April 2008, 20:02

Quote: (Originally Posted by silent running)

Hello sfld, I'm not sure I understand-your primary handset also controls the solenoid firing? And if so, why isn't the HUD programed to tell you that one of your handsets has stopped working or at least blink/vibrate to tell you that your PO2 is below SP or falling?

And why don't you look at your HUD? Do you have it mounted somewhere other than the DSV? -Andy

Yes, quite. Mine goes basically from green to another colour - really not hard to notice?

Meng_Tze · 1st April 2008, 21:38

see here:
http://www.rebreatherworld.com/gener...-zero-viz.html

**Gill Envy** · 1st April 2008, 23:40

Alarmist, hmm, perhaps you missed my point.

anyway, Alarmist to me is the suggestion that because Mark could not maintain set point with his eyes closed on a manual system, that manual systems are somehow less appropriate for situations that involve risk of zero viz. I'm the first to admit i'm not a cave diver but suggesting that Mark's HUD could not have gotten him through even the worst silt out seems un-plausible and a little disingenuous... a good exercise perhaps, but a manual system without a HUD in an overhead environment with silt out potential is not a fair comparison when Mark would have had access to at least occasional glances at his HUD, at the very least he could press his shearwater HUD against his mask as I've shown in this video:
http://www.rebreatherworld.com/gener...-zero-viz.html

I say throw a bag over his head for this exercise (sorry mark), or lower the set point of the eCCR divers and make them dive manually for that part if you want a real comparison.

g

Quote: (Originally Posted by silent running)

Hi Gill, IMHO, stating that you need shorter monitoring intervals with an ECCR is alarmist, as with a HUD you will know if your solenoid stops working as the HUD will show you are below SP. This is what happened to me when mine stopped working. But I knew even before my HUD told me because I could hear the solenoid blocking up.

Call me lazy, but during a period of high stress/work I'd rather not have to remember to push a button, count to 120 or check to see if my loop volume has decreased. I'd much rather use all available brain power and both my hands to try and find a line or my buddy's leg during a silt out...

1st April 2008, 08:17	#61 (permalink)
gtzavelas Rebreather World Writer Current Rebreather/s: Megalodon RB80 / Clone Other Rebreather/s: RB80 / Clone Join Date: Jan 2006 Location: Athens,Greece Posts: 261	Re: mCCR and zero viz exit Here is a neat trick to solve this problem Unfortunately I don’t recall who told me so to pass the credit. Take a small transparent plastic bag (the one used to store food – ziplock type). Fill in the bag with clear water at the start of the dive and tie it up (put around a bit more than cup of water) Put the back in your dry suit pocket When you enter complete silt out zone take bag out of pocket and: Stick it in front of your mask and then stick your computer/handset in front of the bag and squeeze so the bag is squeezed between the mask and the handset If the computer/handset has a light then it will be perfectly visible I have tried and it works!
(Online)

1st April 2008, 08:40	#62 (permalink)
nskdrs New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Classic Kiss Not Bought Yet Join Date: Sep 2005 Location: germany Posts: 95	Re: mCCR and zero viz exit Another possible solution: A tube with a diameter matching ones displaysizes, kinda works like a telescope ( planparallel "lenses" ), 5cm tube with flat and clear lids to be pressed like a tunnel onto gauges, displays and computers in "zerozero" viz, needs possibility to spill light inside the tube to be compatible with no-backlight-displays. Friend of mine carries one like this on his "wreckdigger" dives, he's into solodigging inside wrecks so extensively familiar with diving "thick blackwater", he does not use a HUD. Shortsighted divers diving without correction in their masks might need a more sophisticated version with some kind of lenses. Wouldn't it make a nice accessory to be produced by some thirdparty-manufactor... ...at least maybe nice for backing up a HUD on m/eCCR... HTH, Hoffi Last edited by nskdrs : 1st April 2008 at 09:43.
(Offline)

1st April 2008, 11:02	#63 (permalink)
Mdemon SiegeEngine II Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Home Build Join Date: Feb 2007 Location: SWUK Posts: 1,931	Re: mCCR and zero viz exit We've used gin bottles in the same way. I like the idea of plastic bags though. Ironic, given the title of the thread, that the HUD which does give deco info is slapped on a very expensive eCCR, namely the Boris. Or you could wait until the X1 gets its 4th cell add-on. Then you'd have depth, direction(compass), PO2, deco ceiling all in one place. I did toy with the idea of mounting mine on my BOV, but I reckoned tapping it would be tricky... An OLED screen helps significantly with murk. Perhaps OLED screens for your handsets might help? They're dirt cheap, no pun intended. __________________ www.southwestmafia.com "small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!" The WRONG Attitude will get you killed. "Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"
(Offline)

1st April 2008, 18:14	#64 (permalink)
silent running Mature mouth breather Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Jun 2005 Location: U.S.A. Brooklyn, New York Posts: 1,836	Re: mCCR and zero viz exit Quote: (Originally Posted by Gill Envy) After watching a solenoid stop working mid dive and then start working spontaniously (and that was after a trip back to the hatchery) I've come to the conclusion that eCCR's need an even shorter monitoring interval than mCCR's as you have no MFO and even less time to react to a failing set point controller and no obvious way of calculating the timing of a failure. Hi Gill, IMHO, stating that you need shorter monitoring intervals with an ECCR is alarmist, as with a HUD you will know if your solenoid stops working as the HUD will show you are below SP. This is what happened to me when mine stopped working. But I knew even before my HUD told me because I could hear the solenoid blocking up. Call me lazy, but during a period of high stress/work I'd rather not have to remember to push a button, count to 120 or check to see if my loop volume has decreased. I'd much rather use all available brain power and both my hands to try and find a line or my buddy's leg during a silt out... Last edited by silent running : 1st April 2008 at 19:27.
(Offline)

1st April 2008, 18:46	#65 (permalink)
sfldiver S.C.R.U.B.'S Photographer Current Rebreather/s: Optima Other Rebreather/s: Join Date: Jul 2007 Location: Pompano Beach, FL Posts: 784	Re: mCCR and zero viz exit Quote: (Originally Posted by silent running) Hi Gill, IMHO, stating that you need shorter monitoring intervals with an ECCR is alarmist, as with a HUD you will know if your solenoid stops working as the HUD will show you are below SP. This is what happened to me when mine stopped working. But I knew even before my HUD told me because I could hear the solenoid blocking up. I absolutely agree that we should have a short monitoring interval when using a eccr. Whether you use your Handset or your HUD, makes no difference to me, just monitor your PO2 frequently when relying on electronics. As I posted on a different thread, I did recently have an incident where my handset completely shut down during a dive. I was diving in very calm conditions and was on my knees in 70 ft of depth at the edge of a wreck taking pictures. I generally do not glance at my HUD very often (I probably should), instead I tend to check my primary handset and 4th cell VR3 fairly regularly - Allows me to monitor NDC and Deco Obligation at the same time as my PO2. When I glanced at my primary handset, it was dead. I glanced at my VR3 and my HUD and noticed my PO2 had already dropped below 1.0, from the 1.2 I had the electronics set at. I manually maintained O2 and called the dive... I now make a conscious effort to monitor my PO2 much more frequently then I previously did, even though I feel as though I was monitoring it at an adequate frequency before! __________________ *Currently piloting & shooting...* Dive Rite O2ptima FX Rigged w/ a Dsix Custom Aluminum Frame, Nomad Wing, Transpac Harness and VR3 Computer w/ VPM-B/E & a 4th Cell Sensor Link.* Canon PowerShot G9 Digital Camera *Rigged in a Patima-PDCH 2008 G9 Aluminum Housing w/ an Inon UWL-100 Achromat Wide Conversion Lens, 2 Inon UCL-165M67 Close-Up Lenses and 2 Inon Z-240 Strobes.
(Offline)

1st April 2008, 19:25	#66 (permalink)
silent running Mature mouth breather Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Jun 2005 Location: U.S.A. Brooklyn, New York Posts: 1,836	Re: mCCR and zero viz exit Quote: (Originally Posted by sfldiver) I absolutely agree that we should have a short monitoring interval when using a eccr. Whether you use your Handset or your HUD, makes no difference to me, just monitor your PO2 frequently when relying on electronics. As I posted on a different thread, I did recently have an incident where my handset completely shut down during a dive. I was diving in very calm conditions and was on my knees in 70 ft of depth at the edge of a wreck taking pictures. I generally do not glance at my HUD very often (I probably should), instead I tend to check my primary handset and 4th cell VR3 fairly regularly - Allows me to monitor NDC and Deco Obligation at the same time as my PO2. When I glanced at my primary handset, it was dead. I glanced at my VR3 and my HUD and noticed my PO2 had already dropped below 1.0, from the 1.2 I had the electronics set at. I manually maintained O2 and called the dive... I now make a conscious effort to monitor my PO2 much more frequently then I previously did, even though I feel as though I was monitoring it at an adequate frequency before! Hello sfld, I'm not sure I understand-your primary handset also controls the solenoid firing? And if so, why isn't the HUD programed to tell you that one of your handsets has stopped working or at least blink/vibrate to tell you that your PO2 is below SP or falling? And why don't you look at your HUD? Do you have it mounted somewhere other than the DSV? -Andy
(Offline)

1st April 2008, 19:54	#67 (permalink)
sfldiver S.C.R.U.B.'S Photographer Current Rebreather/s: Optima Other Rebreather/s: Join Date: Jul 2007 Location: Pompano Beach, FL Posts: 784	Re: mCCR and zero viz exit Quote: (Originally Posted by silent running) Hello sfld, I'm not sure I understand-your primary handset also controls the solenoid firing? And if so, why isn't the HUD programed to tell you that one of your handsets has stopped working or at least blink/vibrate to tell you that your PO2 is below SP or falling? And why don't you look at your HUD? Do you have it mounted somewhere other than the DSV? -Andy Yep, the primary handset controls the selenoid firing, so when it goes out, your PO2 drops. The HUD will not not notify me if the primary handset shuts down, because the HUD is controlled by the secondary for redundancy purposes and will continue to blink the current PO2. However, should the PO2 drop or rise to critical levels, heavy vibration will immediately alert me to a problem, and the selenoid will ultimately fire automatically if the PO2 gets too low. That's my understanding of the system. I do not generally look at my HUD, because when I took my class, I had lots of difficultly adjusting the HUD to a point where I could clearly see it, so during training, I got in the habit of monitoring my handsets and not the HUD. Since then, I've continued the habit, which is probably something I need to work on. However, keep in mind, I also have the habit of constantly monitoring my handsets, which comes from my deep diving tech days, because I always wanted to know what my deco obligation was climbing to, so now I just monitor my PO2 and check my deco via the handsets frequently. __________________ *Currently piloting & shooting...* Dive Rite O2ptima FX Rigged w/ a Dsix Custom Aluminum Frame, Nomad Wing, Transpac Harness and VR3 Computer w/ VPM-B/E & a 4th Cell Sensor Link.* Canon PowerShot G9 Digital Camera Rigged in a Patima-PDCH 2008 G9 Aluminum Housing w/ an Inon UWL-100 Achromat Wide Conversion Lens, 2 Inon UCL-165M67 Close-Up Lenses and 2 Inon Z-240 Strobes. Last edited by sfldiver : 1st April 2008 at 19:58.*
(Offline)

1st April 2008, 20:02	#68 (permalink)
Mdemon SiegeEngine II Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Home Build Join Date: Feb 2007 Location: SWUK Posts: 1,931	Re: mCCR and zero viz exit Quote: (Originally Posted by silent running) Hello sfld, I'm not sure I understand-your primary handset also controls the solenoid firing? And if so, why isn't the HUD programed to tell you that one of your handsets has stopped working or at least blink/vibrate to tell you that your PO2 is below SP or falling? And why don't you look at your HUD? Do you have it mounted somewhere other than the DSV? -Andy Yes, quite. Mine goes basically from green to another colour - really not hard to notice? __________________ www.southwestmafia.com "small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!" The WRONG Attitude will get you killed. "Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"
(Offline)

1st April 2008, 21:38	#69 (permalink)
Meng_Tze 246 Bubbleless Cove Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Jan 2007 Location: FL, USA Posts: 111	Re: mCCR and zero viz exit see here: http://www.rebreatherworld.com/gener...-zero-viz.html __________________ Homo Bonae Voluntatis
(Offline)

1st April 2008, 23:40	#70 (permalink)
Gill Envy Shearwater Copis Divers Current Rebreather/s: Other CCR Other Rebreather/s: Evolution Other CCR Join Date: Nov 2005 Location: seattle Posts: 1,326	Re: mCCR and zero viz exit Alarmist, hmm, perhaps you missed my point. anyway, Alarmist to me is the suggestion that because Mark could not maintain set point with his eyes closed on a manual system, that manual systems are somehow less appropriate for situations that involve risk of zero viz. I'm the first to admit i'm not a cave diver but suggesting that Mark's HUD could not have gotten him through even the worst silt out seems un-plausible and a little disingenuous... a good exercise perhaps, but a manual system without a HUD in an overhead environment with silt out potential is not a fair comparison when Mark would have had access to at least occasional glances at his HUD, at the very least he could press his shearwater HUD against his mask as I've shown in this video: http://www.rebreatherworld.com/gener...-zero-viz.html I say throw a bag over his head for this exercise (sorry mark), or lower the set point of the eCCR divers and make them dive manually for that part if you want a real comparison. g Quote: (Originally Posted by silent running) Hi Gill, IMHO, stating that you need shorter monitoring intervals with an ECCR is alarmist, as with a HUD you will know if your solenoid stops working as the HUD will show you are below SP. This is what happened to me when mine stopped working. But I knew even before my HUD told me because I could hear the solenoid blocking up. Call me lazy, but during a period of high stress/work I'd rather not have to remember to push a button, count to 120 or check to see if my loop volume has decreased. I'd much rather use all available brain power and both my hands to try and find a line or my buddy's leg during a silt out... __________________ Gill Envy ...Because I wasn't born with gills! ><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°> Last edited by Gill Envy : 2nd April 2008 at 00:30.
(Offline)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode