Backup Computer Recommendations?

[savsuds]

Huh? Isn't my Oceanic Atom a PPS computer?

I have gone into deco on it numerous times. The deco on it always clears by the time I actually get out and it doesn't lock me out.

Regardless of whether Oceanic are PPS or not, as far as I know, no computer will lock you out unless you go into deco AND skip the stops it tells you to do. The only problem with going into deco on something like a Suunto (from what little I know) is that it will give you longer deco stops and shorter NDLs on repetitive dives after that, as compared to other computers.

My apologies. My GEO locks me out. I tend to ignore the OCI, way too pricey.

 

[stuartv]

To answer your question about the sort of dives, they will be in the 130 foot to 180' depth range with lots of wreck penetrations. Planned deco on almost all of the dives as we will be wanting to maximize bottom time..

Are you going to be doing gas switches to a deco gas? Or just using one gas for bottom and all deco?

 

[stuartv]

My apologies. My GEO locks me out. I tend to ignore the OCI, way too pricey.

Your Geo locks you out if you go into deco and you follow all the stops it tells you to? Or only if you skip the prescribed stops? I thought the Geo was almost identical to my Atom, save for not having wireless AI capability.

 

[savsuds]

Your Geo locks you out if you go into deco and you follow all the stops it tells you to? Or only if you skip the prescribed stops? I thought the Geo was almost identical to my Atom, save for not having wireless AI capability.

A dive buddy and me went on a couple boat dives together. He has 2 Atoms, I had a Geo and Aeris A300CS OLED. First dive to 125ft for the max time. I stayed about 5ft shallower than him the whole time. Surface time was about an hour. The second dive we were coke bottle hunting at 100-110ft. On the descent my Geo went into gauge mode. My Aeris however was a little more liberal with the NDL and was my primary DC. I was not afforded the opportunity to follow its recommendation. Had to stick with my buddy and my primary DC was still cool, so we did not turn the dive around. We tip toed the NDL limits for our computers at 110 before ascending. We did follow our computers recommended deep stops on our ascent. The Geo still was an unhappy camper and refused to come back to life even with 30 minutes of bottle hunting at 15-20ft towards the end of our dive. I had 2 more dives that day where I was 15-20ft above a different dive buddy. We both were equipped to dive solo, but stayed together mostly.The Geo came out of gauge mode the following day. Which we decided should not be back to back deep days.

EDIT: My early morning dive buddy got the Nickname 1 bar after that day. He woke the next morning with 1 bar showing on his Atom still.

 

[kcprofessor]

Are you going to be doing gas switches to a deco gas? Or just using one gas for bottom and all deco

For the first few dives, I doubt an alternate gas mix will be required, but we'll probably carry the deco cylinders filled with the bottom mix and switch gasses just to get back in practice. For the deeper dives, we will probably use EAN50.
That being said, I feel that any backup computer must track the primary pretty closely. My buddy and I both dive Shearwaters, so our deco profiles are the very close. If one of us was diving a HelO2, the deco times would be out of sync and the HelO2 diver would become very unpopular! Part of that is due to the Suunto adaptation of the RGBM which seems to add gobs of deco time at shallow depths.

 

[stuartv]

A dive buddy and me went on a couple boat dives together. He has 2 Atoms, I had a Geo and Aeris A300CS OLED. First dive to 125ft for the max time. I stayed about 5ft shallower than him the whole time. Surface time was about an hour. The second dive we were coke bottle hunting at 100-110ft. On the descent my Geo went into gauge mode. My Aeris however was a little more liberal with the NDL and was my primary DC. I was not afforded the opportunity to follow its recommendation. Had to stick with my buddy and my primary DC was still cool, so we did not turn the dive around. We tip toed the NDL limits for our computers at 110 before ascending. We did follow our computers recommended deep stops on our ascent. The Geo still was an unhappy camper and refused to come back to life even with 30 minutes of bottle hunting at 15-20ft towards the end of our dive. I had 2 more dives that day where I was 15-20ft above a different dive buddy. We both were equipped to dive solo, but stayed together mostly.The Geo came out of gauge mode the following day. Which we decided should not be back to back deep days.

EDIT: My early morning dive buddy got the Nickname 1 bar after that day. He woke the next morning with 1 bar showing on his Atom still.

I haven't read the Geo manual, but the behavior you described is exactly what I would expect my Atom to do if I ignored it on the first dive and skipped a required deco stop. I actually have done that once, with my Atom, where I was following my tech computer and using a deco gas that the Atom didn't know about. That one time, the Atom thought I skipped a required stop and went into Violation mode and would only work in Gauge mode after that for, I think, 24 hours. At least, it was in Vio mode the rest of the day and the next morning and then I was done diving.

For the first few dives, I doubt an alternate gas mix will be required, but we'll probably carry the deco cylinders filled with the bottom mix and switch gasses just to get back in practice. For the deeper dives, we will probably use EAN50.
That being said, I feel that any backup computer must track the primary pretty closely. My buddy and I both dive Shearwaters, so our deco profiles are the very close. If one of us was diving a HelO2, the deco times would be out of sync and the HelO2 diver would become very unpopular! Part of that is due to the Suunto adaptation of the RGBM which seems to add gobs of deco time at shallow depths.

With gas switches in the cards and that much money invested in the trip, I would want another proper tech computer, for sure. One with multi gas and Gradient Factors. With a $500 budget, I don't know of any other option than the Nitek for $400. Or, as someone said, borrow someone's Shearwater. Or maybe even try to rent one. Rental for a week or two would still probably cost less than the money you'll lose by buying a Nitek and selling it later.

 

[stuartv]

This guy is asking $600 for a used Petrel 2...

For Sale - Shearwater Petrel 2 SA

 

[lermontov]

dont hold back on crucial equipment such as DC and quality regs -its cheap insurance - as i used to say to my motorbike friends if you have a $50 head buy a $50 helmet

 

[stuartv]

dont hold back on crucial equipment such as DC and quality regs -its cheap insurance - as i used to say to my motorbike friends if you have a $50 head buy a $50 helmet

OTOH, $700 for an Arai when you could spend $180 on a Bell is really a waste of money (from a 20-year Arai wearer). There is a (relatively low) point where, after that, more money does not actually get you anything but "prestige".

If a $200 computer does everything you want or need it to and it never gives you any reason to need to call for service or support, then an $850 computer really does not give you anything for the extra money.

 

[beester]

Very simple: use your perdix and keep your helo as gauge. If the perdix fails make sure you have backup plans for the same deco model and GF settings, which you can use on the fly. Or even better, dive the plan keep your perdix as backup Finally have a team/buddies who are diving the same plan.

A computer should not replace a brain, just be a backup of it... I always find it curious that so many people find it so hard to just dive a plan.