Sentinel LSS - Trip Report

Drmike · 27th March 2008, 14:05

Quote: (Originally Posted by Mikel-Deko)

Alright... the sentinel is just for "" NO BOAT DIVE""

so were side scanning, and my gears all prepped, pre dive tested and good to go.
engines suddenly stops - we rush the wheelhouse as we slow to a crawl and watch the image slowly creaping up the monitor screen
theres a nice virgin wreck below us,

half a dozen eager divers are gearing up and jumping in sporting crowbars axes and huge liftbags.

but my unit has timed out and gone back to sleep mode!! Have to go through pre dive procedure again!

and Im sat there pre breathing for 5 long long long mins!!!

aghhhhh!!!!

I know its a good thing from a safety perspective - but really!!! theres only one - maybe 2 bells you know!!!

Mark Chase · 27th March 2008, 17:09

Quote: (Originally Posted by Drmike)

so were side scanning, and my gears all prepped, pre dive tested and good to go.
engines suddenly stops - we rush the wheelhouse as we slow to a crawl and watch the image slowly creaping up the monitor screen
theres a nice virgin wreck below us,

half a dozen eager divers are gearing up and jumping in sporting crowbars axes and huge liftbags.

but my unit has timed out and gone back to sleep mode!! Have to go through pre dive procedure again!

and Im sat there pre breathing for 5 long long long mins!!!

aghhhhh!!!!

I know its a good thing from a safety perspective - but really!!! theres only one - maybe 2 bells you know!!!

Absofriginglootly.

Mind you, in truth i am repelled by the idea of a unit that has that much control over you (they should call it HALL) but in fact id do my predive checks before jumping in even if we mored up over the bullion wreck following a storm.

These CCR things really scare me. I reckon the ultimate safety device would be a hologram image of my two kids emerging when i switch the hand sets on. Under neath the image should be a text saying don't be a selfish bastard, do your predive checks now.

ATB

Mark

Barrie Law · 27th March 2008, 20:52

Hi Mike,

The Pre Breathe is similar to the Boris but not exactly the same with the Sentinel LSS you can do a Pre Breathe and leave it for up to 30 mins and it will only do a shorter minimal check sequence with four screens before going into the water. It will however allow you to get straight into the water without manually switching it on and it will sustain life by maintaining a minium PPO2 of 0.4 but this is for emergency situations.

Most divers would do pre-dive checks and to have them in a sequence on the CCR primary handset is a good idea and it will help to ensure proper checks are carried out before diving the Sentinel LSS.

Here are a few pictures from the trip.

Drmike · 28th March 2008, 02:45

Thanks Barrie,

Mark, I also always do a full predive test before every dive including a 02 flush to verify cal and ensure i hit the surface with elevated ppo2- but I can fly through that quite quickly and easily in just a few mins, I can do it an hour before the dive for eg and leave my unit prepped and ready to go. Before I hit the water Id scroll through the pre dive tests screens and go dive. But with the Sentinel requiring a 5 mins breathe that has to be done 30mins or less before a dive (rather than screen skipped through) then a 5 min prebreathe may feel like a lifetime all geared up under a 32degC sun and your the last on the boat. (dont you just hate the sound of steel clanging against rusty metal as your pulling down the line

)

Having a longer 30 min countdown should help though and shows that these guys do look at all the angles.

To be honest the pre breathe is the one test I tend not to do properly. I do maybe a min or two at most. I am not wholey sure if a 5min prebreathe would highlight anything but reasonble sized bypasses - but I may be wrong (this has been my internatl justification for not really doing full 5 min) I recall reading something yonks ago about the validity of pre breathes but I may have recalled that wrong - does anyone have any data on that?? Happy to change my procedures if shown to be valid

I note the manual shut off valves are in the manual injector blocks...hmm not sure I like that position. easy to get to but how easy to knock closed by accident?

**DeepBlueInnovation** · 28th March 2008, 03:23

I could be mistaken, but I believe the 5 minute pre-breathe on units is primarily for colder climes. If you are diving in warm climates then activating the chemical reaction in the scrubber shouldn't take very long and I imagine 1 or two minutes would be sufficient.

Can someone with better chemical knowledge than I correct me if I am mistaken?

Cheers,

Ben.

JonnyB · 28th March 2008, 05:31

Quote: (Originally Posted by DeepBlueInnovation)

I could be mistaken, but I believe the 5 minute pre-breathe on units is primarily for colder climes. If you are diving in warm climates then activating the chemical reaction in the scrubber shouldn't take very long and I imagine 1 or two minutes would be sufficient.

Can someone with better chemical knowledge than I correct me if I am mistaken?

Cheers,

Ben.

That is true, but i do not believe someone would build in that as a functionality in their software.
Much better if they have one time for pre breading.

/Jonny

paulraymaekers · 28th March 2008, 05:36

Quote: (Originally Posted by DeepBlueInnovation)

I could be mistaken, but I believe the 5 minute pre-breathe on units is primarily for colder climes. If you are diving in warm climates then activating the chemical reaction in the scrubber shouldn't take very long and I imagine 1 or two minutes would be sufficient.

Can someone with better chemical knowledge than I correct me if I am mistaken?

Cheers,

Ben.

Ben, I think the concept of pre-breathing has nearly nothing to do with activating your scrubber (except for temp around freezing temp), but more as a general test for your functioning rebreather: does it work or not!
meaning, cells, verifiing befhaviour of cells, is the scrubber working or do you feel weard when breathing (did you pack the scrubber correct, or at all) etc etc etc

paul

tecdivertraining · 28th March 2008, 05:56

Quote: (Originally Posted by paulraymaekers)

Ben, I think the concept of pre-breathing has nearly nothing to do with activating your scrubber (except for temp around freezing temp), but more as a general test for your functioning rebreather: does it work or not!
meaning, cells, verifiing befhaviour of cells, is the scrubber working or do you feel weard when breathing (did you pack the scrubber correct, or at all) etc etc etc

paul

I respect that it would check the cells and solonoid but i dont think it will show CO2 breakthrough in the short time, personal testing shows no signs until around 10 minutes with NO scrubber in the unit.

***Beanie*** · 28th March 2008, 07:33

Quote: (Originally Posted by Drmike)

I note the manual shut off valves are in the manual injector blocks...hmm not sure I like that position. easy to get to but how easy to knock closed by accident?

Assuming there not massivly different from the pre production ones, I would think that it would be difficult to accidentaly slide them off.

paulraymaekers · 28th March 2008, 09:51

Quote: (Originally Posted by tecdivertraining)

I respect that it would check the cells and solonoid but i dont think it will show CO2 breakthrough in the short time, personal testing shows no signs until around 10 minutes with NO scrubber in the unit.

Hello Matt, if you can breath 10 minutes from a unit with NO scrubber inside, withouth any signs..

paul

27th March 2008, 14:05	#31 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,128	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by Mikel-Deko) Alright... the sentinel is just for "" NO BOAT DIVE"" so were side scanning, and my gears all prepped, pre dive tested and good to go. engines suddenly stops - we rush the wheelhouse as we slow to a crawl and watch the image slowly creaping up the monitor screen theres a nice virgin wreck below us, half a dozen eager divers are gearing up and jumping in sporting crowbars axes and huge liftbags. but my unit has timed out and gone back to sleep mode!! Have to go through pre dive procedure again! and Im sat there pre breathing for 5 long long long mins!!! aghhhhh!!!! I know its a good thing from a safety perspective - but really!!! theres only one - maybe 2 bells you know!!! __________________ Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you Last edited by Drmike : 27th March 2008 at 14:07.
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27th March 2008, 17:09	#32 (permalink)
Mark Chase I go down for ages Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Jan 2005 Location: Kent Posts: 2,470	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by Drmike) so were side scanning, and my gears all prepped, pre dive tested and good to go. engines suddenly stops - we rush the wheelhouse as we slow to a crawl and watch the image slowly creaping up the monitor screen theres a nice virgin wreck below us, half a dozen eager divers are gearing up and jumping in sporting crowbars axes and huge liftbags. but my unit has timed out and gone back to sleep mode!! Have to go through pre dive procedure again! and Im sat there pre breathing for 5 long long long mins!!! aghhhhh!!!! I know its a good thing from a safety perspective - but really!!! theres only one - maybe 2 bells you know!!! Absofriginglootly. Mind you, in truth i am repelled by the idea of a unit that has that much control over you (they should call it HALL) but in fact id do my predive checks before jumping in even if we mored up over the bullion wreck following a storm. These CCR things really scare me. I reckon the ultimate safety device would be a hologram image of my two kids emerging when i switch the hand sets on. Under neath the image should be a text saying don't be a selfish bastard, do your predive checks now. ATB Mark __________________ Is it supposed to make that noise ? I took my unit to the dive shop and demanded they bolt on every thing that would fit. Join my elite diving teem and get a Tshirt "Doing It Chasey"Hammerhead Eccr Advanced Diving System
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28th March 2008, 02:45	#34 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,128	Re: Sentinel LSS - Trip Report Thanks Barrie, Mark, I also always do a full predive test before every dive including a 02 flush to verify cal and ensure i hit the surface with elevated ppo2- but I can fly through that quite quickly and easily in just a few mins, I can do it an hour before the dive for eg and leave my unit prepped and ready to go. Before I hit the water Id scroll through the pre dive tests screens and go dive. But with the Sentinel requiring a 5 mins breathe that has to be done 30mins or less before a dive (rather than screen skipped through) then a 5 min prebreathe may feel like a lifetime all geared up under a 32degC sun and your the last on the boat. (dont you just hate the sound of steel clanging against rusty metal as your pulling down the line ) Having a longer 30 min countdown should help though and shows that these guys do look at all the angles. To be honest the pre breathe is the one test I tend not to do properly. I do maybe a min or two at most. I am not wholey sure if a 5min prebreathe would highlight anything but reasonble sized bypasses - but I may be wrong (this has been my internatl justification for not really doing full 5 min) I recall reading something yonks ago about the validity of pre breathes but I may have recalled that wrong - does anyone have any data on that?? Happy to change my procedures if shown to be valid I note the manual shut off valves are in the manual injector blocks...hmm not sure I like that position. easy to get to but how easy to knock closed by accident? __________________ Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you Last edited by Drmike : 28th March 2008 at 03:00.
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28th March 2008, 03:23	#35 (permalink)
DeepBlueInnovation Prism #007 Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Sep 2005 Location: Perth, Western Australia Posts: 312	Re: Sentinel LSS - Trip Report I could be mistaken, but I believe the 5 minute pre-breathe on units is primarily for colder climes. If you are diving in warm climates then activating the chemical reaction in the scrubber shouldn't take very long and I imagine 1 or two minutes would be sufficient. Can someone with better chemical knowledge than I correct me if I am mistaken? Cheers, Ben.
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28th March 2008, 05:31	#36 (permalink)
JonnyB Jonny The Hatch Current Rebreather/s: MK 15.X Titan Other CCR Other SCR Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic Megalodon Sport Kiss Classic Kiss Other CCR Other SCR Home Build Join Date: Jan 2005 Location: Sweden (Stockholm)/Cyprus(Ayia Napa) Posts: 944	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by DeepBlueInnovation) I could be mistaken, but I believe the 5 minute pre-breathe on units is primarily for colder climes. If you are diving in warm climates then activating the chemical reaction in the scrubber shouldn't take very long and I imagine 1 or two minutes would be sufficient. Can someone with better chemical knowledge than I correct me if I am mistaken? Cheers, Ben. That is true, but i do not believe someone would build in that as a functionality in their software. Much better if they have one time for pre breading. /Jonny __________________ A quote from Crazyduck - In remembering our own Rob Davies. "Outbound flight 777 heavy you are cleared for flight Due west into that warm red Texas sunset You have angels on your wings and divers memories on your six." Rest In Peace http://www.divetekcyprus.com http://www.diveccr.com
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28th March 2008, 05:36	#37 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,381	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by DeepBlueInnovation) I could be mistaken, but I believe the 5 minute pre-breathe on units is primarily for colder climes. If you are diving in warm climates then activating the chemical reaction in the scrubber shouldn't take very long and I imagine 1 or two minutes would be sufficient. Can someone with better chemical knowledge than I correct me if I am mistaken? Cheers, Ben. Ben, I think the concept of pre-breathing has nearly nothing to do with activating your scrubber (except for temp around freezing temp), but more as a general test for your functioning rebreather: does it work or not! meaning, cells, verifiing befhaviour of cells, is the scrubber working or do you feel weard when breathing (did you pack the scrubber correct, or at all) etc etc etc paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
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28th March 2008, 05:56	#38 (permalink)
tecdivertraining RebreatherWorld Sponsor Current Rebreather/s: Inspiration Classic Inspiration Vision Evolution Megalodon Dolphin Other Rebreather/s: Not Bought Yet Dolphin Join Date: May 2005 Location: Phuket, Thailand Posts: 401	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by paulraymaekers) Ben, I think the concept of pre-breathing has nearly nothing to do with activating your scrubber (except for temp around freezing temp), but more as a general test for your functioning rebreather: does it work or not! meaning, cells, verifiing befhaviour of cells, is the scrubber working or do you feel weard when breathing (did you pack the scrubber correct, or at all) etc etc etc paul I respect that it would check the cells and solonoid but i dont think it will show CO2 breakthrough in the short time, personal testing shows no signs until around 10 minutes with NO scrubber in the unit. __________________ Mathew Partridge Technical Director Pro-Tech Dive College www.protechdivers.com www.tech-ccr.com
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28th March 2008, 07:33	#39 (permalink)
*Beanie* Politeness officer Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,163	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by Drmike) I note the manual shut off valves are in the manual injector blocks...hmm not sure I like that position. easy to get to but how easy to knock closed by accident? Assuming there not massivly different from the pre production ones, I would think that it would be difficult to accidentaly slide them off. __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk www.divelife.co.uk
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28th March 2008, 09:51	#40 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,381	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by tecdivertraining) I respect that it would check the cells and solonoid but i dont think it will show CO2 breakthrough in the short time, personal testing shows no signs until around 10 minutes with NO scrubber in the unit. Hello Matt, if you can breath 10 minutes from a unit with NO scrubber inside, withouth any signs.. paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
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