Impressions of the Shearwater HUD

silentscuba · 19th February 2007, 14:00

The Shearwater HUD (SW) and constant/integrated PO2 Trimix Dive Computer are manufactured by Bruce Partridge in Vancouver BC. Bruce is great to work with and provides superior customer support.

The Shearwater (SW) HUD is calibrated with oxygen. This is easily achieved by filling the loop on a KISS Classic with oxygen (with proper technique of course). Once the loop is at 1.00 atm partial pressure of oxygen then the HUD can be calibrated.

To calibrate the SW HUD, simply turn it on with one button push then push the same button three times in a second. All three red LED lights will stay on for 5 seconds and then the three LEDs will turn amber confirming the calibration. It is important to know that the loop must be at 1.00 atm of oxygen. So if the user is at altitude then it is best to calibrate at sea level before the trip to altitude and hope you do not need to change a cell.

The SW HUD uses three colors, starting with amber meaning a PO2 of 1.0 atm. Each green flash will mean 0.1 atm above 1.0, so two green flashes means a PO2 of 1.2 atm, three green flashes is 1.3 atm and so on. Red flashes work in the opposite direction and subtract a PO2 of 0.1 atm per flash from 1.0 atm. One red flash will mean a PO2 of 0.9 atm, two red flashes will be 0.8atm and so on.

The SW HUD has three LEDs displaying the PO2 of each cell at the same time. This is a functional concept when comparing to a one LED system that scrolls through all three cells. The three LEDs mean much less flashing as compared to the design where one LED is scrolling through all three cells. This allows the diver to become more in-tune with "lots of flashing means a problem", and will draw attention immediately. Also the three LEDs flash each cells PO2 together. So, if one cell is different it will not flash the same amount once again bringing immediate attention to the problem.

In my opinion, this design concept gives the diver a comparison right in front of their eye that is very difficult to miss or “tune out", and will help the diver maintain a more strict control over their PO2.

The SW HUD is to augment PO2 monitoring not replace it. Also the SW HUD can offer redundancy to a single display system in certain applications. This redundancy will depend on how the HUD is installed and what the actual failure in the system is which could require a diver to go to the redundant / backup system. This is best discussed with the CCR manufactures and the SW HUD manufacture.

The SW HUD can be used on most other CCRs. I have seen it used also on a Megalodon.

On a Megalodon the best way to calibrate the HUD is to use the head caps to fill the head only with oxygen. Assuming you do not want to use the head caps then filling the megalodon loop with oxygen would work to, but this is much more wasteful on the oxygen supply and perhaps less accurate (once again this is determined by user technique).

Like on the KISS, it is important to know that the loop must be at 1.00 atm of oxygen. So if the user is at altitude then it is best to calibrate at sea level before the trip to altitude and hope you do not need to change a cell.

A more controversial way to calibrate the HUD at altitude on a COPIS Meg (and I am NOT TELLING you to do this) is to first set the COPIS PO2 displays at the appropriate PO2 for the altitude using conversion charts. Then flow oxygen into the head until the COPIS display reads as high as it will go. Now for the controversial and tricky part. The out flow tube from the head calibration kit needs to be gently squeezed until the COPIS PO2 display reads 1.00 atm, now, you calibrate the SW HUD. The reason for this is the SW HUD needs to be calibrated 1.00 atm of oxygen. At altitude you cannot achieve this PO2 on land. So if you set the COPIS display PO2 correctly according to the tables then you can be fairly certain by increasing the backpressure into the head and bringing the PO2 to a 1.00 atm that the SW HUD will be correctly calibrated. This is a tricky procedure as you need to not only need to keep pressure on the outflow tube (so the PO2 reads 1.00 atm) but also push the SW HUD button 3 times in a row in less than a second! So like I said if at all possible calibrate at sea level before an altitude dive, this is a much safer way to calibrate.

Overall I am extremely happy with my Shearwater HUD

.

I can honestly say it really does make cell differences and a problem stand out. It also does draw your attention to "lots of flashing" since it does not flash lots when the diver is in a normal PO2 range.

The Shearwater HUD is another great tool the CCR diver has available to them. It can help you maintain a more constant desired PO2 and increase diver safety.

jo_c · 19th February 2007, 14:17

Sounds great! Think I might be ordering one of these soon... (Mel leave space in your suitcase to bring it down to me in May

)

scubagrunt · 19th February 2007, 14:19

Quote: (Originally Posted by jo_c)

Sounds great! Think I might be ordering one of these soon... (Mel leave space in your suitcase to bring it down to me in May

)

your on Jo!!!

Ben Field · 19th February 2007, 14:22

Thanks for the review, mines "in the post" so this only serves to further whet my appetite until it arrives.

One question- did you mount the HUD battery/control box on the breathing hoses as suggested or elsewhere, I'll work out where I want it when it arrives but interested in any pros/cons you've uncovered?

Thanks,
BEN

scubagrunt · 19th February 2007, 14:48

Quote: (Originally Posted by Ben Field)

Thanks for the review, mines "in the post" so this only serves to further whet my appetite until it arrives.

One question- did you mount the HUD battery/control box on the breathing hoses as suggested or elsewhere, I'll work out where I want it when it arrives but interested in any pros/cons you've uncovered?

Thanks,
BEN

mount the box on the breathing hose. it comes with velcro and is easy. no cons only pros in my mind

. i guess if you consider mounting the box on your breathing hose with velcro a con then that would be it.

Padowan · 19th February 2007, 16:37

I have one, and am incredible happy with it. I originally had the box inside the black and yellow case of my inspiration, but on a recent dive, I must have manged to knock the switch and turn it off on entry, and so did the dive without it, and felt rather naked.

I now have the box on the breathing hose (from the scrubber to the T-Piece) and I can reach back and turn it on/off in much the same way as I can switch the ADV shut off on and off on the opposite side.

Helium_diver · 19th February 2007, 17:52

Just installed one on my Classic Kiss. Easy install really well built.Haven't had the chance to dive it but real soon.

Helium_diver

Russ · 19th February 2007, 18:24

Anyone know the depth rating on the HUD? I was asked and I had no idea

Russ

***jradomski*** · 19th February 2007, 19:46

Quote: (Originally Posted by silentscuba)

A more controversial way to calibrate the HUD at altitude on a COPIS Meg (and I am NOT TELLING you to do this) is to first set the COPIS PO2 displays at the appropriate PO2 for the altitude using conversion charts. Then flow oxygen into the head until the COPIS display reads as high as it will go. Now for the controversial and tricky part. The out flow tube from the head calibration kit needs to be gently squeezed until the COPIS PO2 display reads 1.00 atm, now, you calibrate the SW HUD. The reason for this is the SW HUD needs to be calibrated 1.00 atm of oxygen. At altitude you cannot achieve this PO2 on land. So if you set the COPIS display PO2 correctly according to the tables then you can be fairly certain by increasing the backpressure into the head and bringing the PO2 to a 1.00 atm that the SW HUD will be correctly calibrated. This is a tricky procedure as you need to not only need to keep pressure on the outflow tube (so the PO2 reads 1.00 atm) but also push the SW HUD button 3 times in a row in less than a second! So like I said if at all possible calibrate at sea level before an altitude dive, this is a much safer way to calibrate.

Curt,
Be very carefule using this method, depending on the altitude, will depend on how much pressure is necessary.. You CAN damage the oxygen cells because the pressure at the face of the cell is greater than the back (connector) side..

***Beanie*** · 19th February 2007, 20:04

Quote: (Originally Posted by Russ)

Anyone know the depth rating on the HUD? I was asked and I had no idea

Russ

100m I think it does say on the shearwater site

I like mine too

19th February 2007, 14:00	#1 (permalink)
silentscuba rEvo CCR Driver Current Rebreather/s: Classic Kiss rEvo Other Rebreather/s: Inspiration Classic rEvo Join Date: Jun 2005 Location: Mill Creek, WA USA Posts: 612	Impressions of the Shearwater HUD The Shearwater HUD (SW) and constant/integrated PO2 Trimix Dive Computer are manufactured by Bruce Partridge in Vancouver BC. Bruce is great to work with and provides superior customer support. The Shearwater (SW) HUD is calibrated with oxygen. This is easily achieved by filling the loop on a KISS Classic with oxygen (with proper technique of course). Once the loop is at 1.00 atm partial pressure of oxygen then the HUD can be calibrated. To calibrate the SW HUD, simply turn it on with one button push then push the same button three times in a second. All three red LED lights will stay on for 5 seconds and then the three LEDs will turn amber confirming the calibration. It is important to know that the loop must be at 1.00 atm of oxygen. So if the user is at altitude then it is best to calibrate at sea level before the trip to altitude and hope you do not need to change a cell. The SW HUD uses three colors, starting with amber meaning a PO2 of 1.0 atm. Each green flash will mean 0.1 atm above 1.0, so two green flashes means a PO2 of 1.2 atm, three green flashes is 1.3 atm and so on. Red flashes work in the opposite direction and subtract a PO2 of 0.1 atm per flash from 1.0 atm. One red flash will mean a PO2 of 0.9 atm, two red flashes will be 0.8atm and so on. The SW HUD has three LEDs displaying the PO2 of each cell at the same time. This is a functional concept when comparing to a one LED system that scrolls through all three cells. The three LEDs mean much less flashing as compared to the design where one LED is scrolling through all three cells. This allows the diver to become more in-tune with "lots of flashing means a problem", and will draw attention immediately. Also the three LEDs flash each cells PO2 together. So, if one cell is different it will not flash the same amount once again bringing immediate attention to the problem. In my opinion, this design concept gives the diver a comparison right in front of their eye that is very difficult to miss or “tune out", and will help the diver maintain a more strict control over their PO2. The SW HUD is to augment PO2 monitoring not replace it. Also the SW HUD can offer redundancy to a single display system in certain applications. This redundancy will depend on how the HUD is installed and what the actual failure in the system is which could require a diver to go to the redundant / backup system. This is best discussed with the CCR manufactures and the SW HUD manufacture. The SW HUD can be used on most other CCRs. I have seen it used also on a Megalodon. On a Megalodon the best way to calibrate the HUD is to use the head caps to fill the head only with oxygen. Assuming you do not want to use the head caps then filling the megalodon loop with oxygen would work to, but this is much more wasteful on the oxygen supply and perhaps less accurate (once again this is determined by user technique). Like on the KISS, it is important to know that the loop must be at 1.00 atm of oxygen. So if the user is at altitude then it is best to calibrate at sea level before the trip to altitude and hope you do not need to change a cell. A more controversial way to calibrate the HUD at altitude on a COPIS Meg (and I am NOT TELLING you to do this) is to first set the COPIS PO2 displays at the appropriate PO2 for the altitude using conversion charts. Then flow oxygen into the head until the COPIS display reads as high as it will go. Now for the controversial and tricky part. The out flow tube from the head calibration kit needs to be gently squeezed until the COPIS PO2 display reads 1.00 atm, now, you calibrate the SW HUD. The reason for this is the SW HUD needs to be calibrated 1.00 atm of oxygen. At altitude you cannot achieve this PO2 on land. So if you set the COPIS display PO2 correctly according to the tables then you can be fairly certain by increasing the backpressure into the head and bringing the PO2 to a 1.00 atm that the SW HUD will be correctly calibrated. This is a tricky procedure as you need to not only need to keep pressure on the outflow tube (so the PO2 reads 1.00 atm) but also push the SW HUD button 3 times in a row in less than a second! So like I said if at all possible calibrate at sea level before an altitude dive, this is a much safer way to calibrate. Overall I am extremely happy with my Shearwater HUD . I can honestly say it really does make cell differences and a problem stand out. It also does draw your attention to "lots of flashing" since it does not flash lots when the diver is in a normal PO2 range. The Shearwater HUD is another great tool the CCR diver has available to them. It can help you maintain a more constant desired PO2 and increase diver safety. __________________ Curt McNamee rEvo CCR Diver KISS CCR Diver www.silentscuba.com Last edited by silentscuba : 19th February 2007 at 14:17.
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19th February 2007, 14:17	#2 (permalink)
jo_c RBW Member Current Rebreather/s: Megalodon Other Rebreather/s: Inspiration Classic Join Date: Jun 2006 Location: Hants, UK Posts: 163	Re: Impressions of the Shearwater HUD Sounds great! Think I might be ordering one of these soon... (Mel leave space in your suitcase to bring it down to me in May )
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19th February 2007, 14:19	#3 (permalink)
scubagrunt CCR Diva Current Rebreather/s: Inspiration Classic Megalodon Classic Kiss Optima rEvo Other CCR Other SCR Other Rebreather/s: Not Bought Yet Inspiration Classic Inspiration Vision Evolution Megalodon Sport Kiss Classic Kiss Optima rEvo Other CCR Other SCR Join Date: May 2005 Location: Washington Posts: 441	Re: Impressions of the Shearwater HUD Quote: (Originally Posted by jo_c) Sounds great! Think I might be ordering one of these soon... (Mel leave space in your suitcase to bring it down to me in May ) your on Jo!!! __________________ "No good deed goes unpunished!" www.silentscuba.com
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19th February 2007, 14:22	#4 (permalink)
Ben Field CK+Shearwater Current Rebreather/s: Classic Kiss Other Rebreather/s: Sport Kiss Join Date: Aug 2005 Location: London, England Posts: 1,746	Re: Impressions of the Shearwater HUD Thanks for the review, mines "in the post" so this only serves to further whet my appetite until it arrives. One question- did you mount the HUD battery/control box on the breathing hoses as suggested or elsewhere, I'll work out where I want it when it arrives but interested in any pros/cons you've uncovered? Thanks, BEN __________________ Know your PPO2, Pre-breath, Use checklists, Validate cells at 6mtrs, Use pure O2 at or near surface, Use a BOV, Don't dive Solo, Change Slime and Cells as recommended by Manufacturer and RTFM! Beware Fridge Suck! www.hugsac.org.uk
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19th February 2007, 14:48	#5 (permalink)
scubagrunt CCR Diva Current Rebreather/s: Inspiration Classic Megalodon Classic Kiss Optima rEvo Other CCR Other SCR Other Rebreather/s: Not Bought Yet Inspiration Classic Inspiration Vision Evolution Megalodon Sport Kiss Classic Kiss Optima rEvo Other CCR Other SCR Join Date: May 2005 Location: Washington Posts: 441	Re: Impressions of the Shearwater HUD Quote: (Originally Posted by Ben Field) Thanks for the review, mines "in the post" so this only serves to further whet my appetite until it arrives. One question- did you mount the HUD battery/control box on the breathing hoses as suggested or elsewhere, I'll work out where I want it when it arrives but interested in any pros/cons you've uncovered? Thanks, BEN mount the box on the breathing hose. it comes with velcro and is easy. no cons only pros in my mind . i guess if you consider mounting the box on your breathing hose with velcro a con then that would be it. __________________ "No good deed goes unpunished!" www.silentscuba.com
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19th February 2007, 16:37	#6 (permalink)
Padowan RBW Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: Exeter, UK. Posts: 524	Re: Impressions of the Shearwater HUD I have one, and am incredible happy with it. I originally had the box inside the black and yellow case of my inspiration, but on a recent dive, I must have manged to knock the switch and turn it off on entry, and so did the dive without it, and felt rather naked. I now have the box on the breathing hose (from the scrubber to the T-Piece) and I can reach back and turn it on/off in much the same way as I can switch the ADV shut off on and off on the opposite side. __________________ Padowan The future's bright, the future's Yellow .....for now padowan.net - Latest Video: Scapa Flow Rebreather Diving
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19th February 2007, 17:52	#7 (permalink)
Helium_diver Has anyone seen my Gerbil Current Rebreather/s: Classic Kiss Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Baltimore MD USA Posts: 151	Re: Impressions of the Shearwater HUD Just installed one on my Classic Kiss. Easy install really well built.Haven't had the chance to dive it but real soon. Helium_diver __________________ "If I look unconscious I probably am " Bill Hartman
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19th February 2007, 18:24	#8 (permalink)
Russ New Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Jul 2006 Posts: 88	Re: Impressions of the Shearwater HUD Anyone know the depth rating on the HUD? I was asked and I had no idea Russ
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19th February 2007, 19:46	#9 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,093	Re: Impressions of the Shearwater HUD Quote: (Originally Posted by silentscuba) A more controversial way to calibrate the HUD at altitude on a COPIS Meg (and I am NOT TELLING you to do this) is to first set the COPIS PO2 displays at the appropriate PO2 for the altitude using conversion charts. Then flow oxygen into the head until the COPIS display reads as high as it will go. Now for the controversial and tricky part. The out flow tube from the head calibration kit needs to be gently squeezed until the COPIS PO2 display reads 1.00 atm, now, you calibrate the SW HUD. The reason for this is the SW HUD needs to be calibrated 1.00 atm of oxygen. At altitude you cannot achieve this PO2 on land. So if you set the COPIS display PO2 correctly according to the tables then you can be fairly certain by increasing the backpressure into the head and bringing the PO2 to a 1.00 atm that the SW HUD will be correctly calibrated. This is a tricky procedure as you need to not only need to keep pressure on the outflow tube (so the PO2 reads 1.00 atm) but also push the SW HUD button 3 times in a row in less than a second! So like I said if at all possible calibrate at sea level before an altitude dive, this is a much safer way to calibrate. Curt, Be very carefule using this method, depending on the altitude, will depend on how much pressure is necessary.. You CAN damage the oxygen cells because the pressure at the face of the cell is greater than the back (connector) side.. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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19th February 2007, 20:04	#10 (permalink)
*Beanie* Gallery Administrator Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,292	Re: Impressions of the Shearwater HUD Quote: (Originally Posted by Russ) Anyone know the depth rating on the HUD? I was asked and I had no idea Russ 100m I think it does say on the shearwater site I like mine too
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