walkonmars
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Need an inexpensive dive computer to backup my AI consoles
- Thread starter Altamira
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I'm all in favor of well made, well designed computers with good user interfaces and easy battery changes, etc... But unless you know that the OP will be doing technical training in the future, I'm not sure why you say this.
Pretty much the cheapest computer available these days will do nitrox. I don't even think that it's possible to buy an air-only computer any more. So what would change to make one of these low end computers "worthless" or "obsolete"? Sure, a Petrel is easier to read, but it's not like that makes a Bud or a Puck useless. They all do exactly the same thing - track tissue loading.
1000RR
Contributor
Here's some information I ran across on a Blog...
Pelagic DSAT - This algorithm is based on the studies that were used to develop the PADI Recreational Dive Planner (RDP) which is used and relied upon by thousands of divers around the world. Oceanic, along with other manufacturers, having been using this algorithm for many years.
Pelagic Z+ - This algorithm was developed to safely maximise dive times at depth without penalising the diver for performing repetitive deeper dives. It takes into account the effects of colder conditions and more rigorous demands on the diver. The algorithm uses the Buhlmann ZHL-16C database which produces very similar dive profiles to the algorithms used in other manufacturer dive computers including Suunto, Uwatec and Mares.
Both of these algorithms allow for additional adjustments to increase the conservatism which will make the dive safer but also reduce the dive bottom time. Deep stops are also supported for no-decompression dives to help safely remove excess nitrogen at a higher rate.
How about some real world scenarios:
Liveaboard (recreational diving) – A week of repetitive diving (30m or less) can start to really load up the nitrogen, reducing your bottom time. Frequent dives and short surface intervals don't allow enough time between dives to effectively off load the build-up and rapidly starts to affect your experience. The Pelagic DSAT was built for handling this type of diving, frequent dives to 30 metres or shallower depths. A diver using this algorithm should notice longer dive times as the week goes on compared to other divers using Suunto, Mares or similar dive computers.
The graph below shows how well tuned the algorithm is for shallower dives. At 30m/100ft all the algorithms offer very similar dive times but by coming up 18m/60ft it has started to separate from the others and can give the diver longer bottom time. A shallow 12m/40ft dive will be significantly longer using the Pelagic DSAT algorithm compared to other brands or even the Oceanic Pelagic Z+ algorithm.
Day or Weekend Diving – Most of us work during the week and dive at the weekend which means we want to make the most of those two precious diving days with maximum bottom time on our favourite wreck or something similar. The Pelagic Z+ algorithm is perfect for deeper dives in more strenuous conditions like cold temperatures. In most cases we'll have longer surface intervals to have a bite to eat, warm up, chat about the dive, etc and the algorithm takes this into account to safely give us as much time in the water as possible. This algorithm will also provide similar dive profiles to those produced by Suunto and Mares.
Pelagic DSAT - This algorithm is based on the studies that were used to develop the PADI Recreational Dive Planner (RDP) which is used and relied upon by thousands of divers around the world. Oceanic, along with other manufacturers, having been using this algorithm for many years.
Pelagic Z+ - This algorithm was developed to safely maximise dive times at depth without penalising the diver for performing repetitive deeper dives. It takes into account the effects of colder conditions and more rigorous demands on the diver. The algorithm uses the Buhlmann ZHL-16C database which produces very similar dive profiles to the algorithms used in other manufacturer dive computers including Suunto, Uwatec and Mares.
Both of these algorithms allow for additional adjustments to increase the conservatism which will make the dive safer but also reduce the dive bottom time. Deep stops are also supported for no-decompression dives to help safely remove excess nitrogen at a higher rate.
How about some real world scenarios:
Liveaboard (recreational diving) – A week of repetitive diving (30m or less) can start to really load up the nitrogen, reducing your bottom time. Frequent dives and short surface intervals don't allow enough time between dives to effectively off load the build-up and rapidly starts to affect your experience. The Pelagic DSAT was built for handling this type of diving, frequent dives to 30 metres or shallower depths. A diver using this algorithm should notice longer dive times as the week goes on compared to other divers using Suunto, Mares or similar dive computers.
The graph below shows how well tuned the algorithm is for shallower dives. At 30m/100ft all the algorithms offer very similar dive times but by coming up 18m/60ft it has started to separate from the others and can give the diver longer bottom time. A shallow 12m/40ft dive will be significantly longer using the Pelagic DSAT algorithm compared to other brands or even the Oceanic Pelagic Z+ algorithm.
Day or Weekend Diving – Most of us work during the week and dive at the weekend which means we want to make the most of those two precious diving days with maximum bottom time on our favourite wreck or something similar. The Pelagic Z+ algorithm is perfect for deeper dives in more strenuous conditions like cold temperatures. In most cases we'll have longer surface intervals to have a bite to eat, warm up, chat about the dive, etc and the algorithm takes this into account to safely give us as much time in the water as possible. This algorithm will also provide similar dive profiles to those produced by Suunto and Mares.
OP
I probably should have put this information in my original post to help focus recommendations on my diving and needs.
Age 72, so I don't see more than 8-10 years more diving. All diving is strictly recreational with most dives in the 60-80' range, occasionally going down to slightly below 100', usually with 2-3 dives per day max. Not going to do any tech diving, and buying a $1000+ computer is not going to happen. When the Atmos AIs die, I will replace them with something comparable as they have met all of our diving needs. Whatever backup computers I get for the Fling trip are going to be just that--backups. Thank you all for any additional recommendations.
Age 72, so I don't see more than 8-10 years more diving. All diving is strictly recreational with most dives in the 60-80' range, occasionally going down to slightly below 100', usually with 2-3 dives per day max. Not going to do any tech diving, and buying a $1000+ computer is not going to happen. When the Atmos AIs die, I will replace them with something comparable as they have met all of our diving needs. Whatever backup computers I get for the Fling trip are going to be just that--backups. Thank you all for any additional recommendations.
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@Altamira I'd grab a pair of some combination of these guys. Big screens, relatively easy to use, nitrox capable obviously, user changeable batteries, etc. They're cheap, they work, and they'll more than likely outlast you diving. With at least the Seiko/Hollis ones, unsure about the Scubapro, they will do 2 gas up to O2 and deco so if your grandson decides to go that route down the road, these will at least grow with him for a little bit
built by Seiko and the same as a bunch of other computers that were sold around that time. Offer $150, and they're pretty much indestructible. Also sold by Zeagle, Cressi, etc. but they're all the same. Nice big screen to boot
Dive Rite Nitek Duo Air/Nitrox Computer | eBay
Cheaper one and in a console which is nice if you want that. If not Deep Sea Supply makes bungee wrist mounts for like $25 that are super slick
DIVE RITE NiTek Duo Scuba diving computer consul in psi with gauge complete | eBay
Same computer just sold by Tusa, again in a console so add in cost of a bungee mount if you want to wrist mount it.
TUSA IQ-700 TRIPLE GAUGE CONSOLE scuba dive diving computer COMPASS DEPTH GAUGE | eBay
User interface is a touch annoying, but they have the same algorithms as your existing computers
Hollis Dg03 Nitrox Dive Computer For Scuba Diving | eBay
no experience with this one, but it's a scubapro so it's probably good. I don't know if @cool_hardware52 makes a boot for that one though....
DIVE COMPUTER SUBGEAR (SCUBAPRO) XP10 | eBay
built by Seiko and the same as a bunch of other computers that were sold around that time. Offer $150, and they're pretty much indestructible. Also sold by Zeagle, Cressi, etc. but they're all the same. Nice big screen to boot
Dive Rite Nitek Duo Air/Nitrox Computer | eBay
Cheaper one and in a console which is nice if you want that. If not Deep Sea Supply makes bungee wrist mounts for like $25 that are super slick
DIVE RITE NiTek Duo Scuba diving computer consul in psi with gauge complete | eBay
Same computer just sold by Tusa, again in a console so add in cost of a bungee mount if you want to wrist mount it.
TUSA IQ-700 TRIPLE GAUGE CONSOLE scuba dive diving computer COMPASS DEPTH GAUGE | eBay
User interface is a touch annoying, but they have the same algorithms as your existing computers
Hollis Dg03 Nitrox Dive Computer For Scuba Diving | eBay
no experience with this one, but it's a scubapro so it's probably good. I don't know if @cool_hardware52 makes a boot for that one though....
DIVE COMPUTER SUBGEAR (SCUBAPRO) XP10 | eBay
walkonmars
Contributor
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I don't understand. The OP didn't say anything about how often he dives with his grandson, but not sure how that is relevant.
If two people are on a dive trip, and if they want to have backup computers (so in case one fails, they don't have to sit out a day), they need four computers.
The OP wasn't looking for any other capabilities, since his current computers serve his needs well, and he will not be doing technical training in the future. He just wants backup.
Why are you recommending that he upgrade his perfectly adequate dive computer? The OPs main concern was that the algorithms be relatively close, but if there was a difference it would be fine to just get out of the water when the first computer of the group reached NDL.
OP
To answer @walkonmars' concerns and points, which I appreciate, and once again, my fault for not being sufficiently specific in my posts.
I/we (wife/dive buddy and I) have two complete set of regs, etc., described earlier. For most of the diving we do, except for the occasional week long trips to Bonaire, etc., we really do not need the computers because of our typical dive profiles, number of consecutive dives and dive days. We bought the computers prior to a week long Bonaire trip in 2010, and have felt the need to have them on a few more dive intensive trips such as an 11 day Paul Gauguin trip where we planned a lot of dives. I dive with my grandson, who uses my wife's regs, etc., about 12 dives (2 dives/day/max 80') a year, and we use the computers on all dives because we have them, but could easily dive without them using the gauge consoles and tables. I really only need the backup computers for this MV Fling trip because computers are required dive items, and because he is 15, I would not want to ask another adult diver to buddy with him in the event either primary computer fails . However, we will happily continue to use them as backups on future dives because we will have them. I hope this information clarifies why I need the extra computers. Thanks again for all of your inputs.
I/we (wife/dive buddy and I) have two complete set of regs, etc., described earlier. For most of the diving we do, except for the occasional week long trips to Bonaire, etc., we really do not need the computers because of our typical dive profiles, number of consecutive dives and dive days. We bought the computers prior to a week long Bonaire trip in 2010, and have felt the need to have them on a few more dive intensive trips such as an 11 day Paul Gauguin trip where we planned a lot of dives. I dive with my grandson, who uses my wife's regs, etc., about 12 dives (2 dives/day/max 80') a year, and we use the computers on all dives because we have them, but could easily dive without them using the gauge consoles and tables. I really only need the backup computers for this MV Fling trip because computers are required dive items, and because he is 15, I would not want to ask another adult diver to buddy with him in the event either primary computer fails . However, we will happily continue to use them as backups on future dives because we will have them. I hope this information clarifies why I need the extra computers. Thanks again for all of your inputs.
Interesting point!
Perhaps I ought to replace all my scuba equipment eg 20 yrs old Uwatec Aladin computer, 20yrs old Apeks DS4 regulators etc etc.
The main function of a recreational dive computer is to calculate ndl. My ageing Aladin is NOT more likely to bend me than a Shearwater! Lighter, smaller and more streamline? What have they got to do with calculating of ndl etc? BTW, my Aladin does not even has light and it hasn't stop me from doing night dive.
I have yet to come across any computer that promised DCS free!
Up grade to a tec computer? What is wrong with pre-dive plan and two bottom timers. Has been doing that since 1998.
tcpip95
Contributor
UPDATE: I actually found a better deal on a brand new Genesis ReAct Pro - $199 w/free shipping from scuba.com. I cancelled the LeisurePro order because they couldn't tell me if it was the old version or the new version. I have a new one, and the old one uses a different interface cable. I now have two identical computers.
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