AI Computers and Backup Analog

[Lorenzoid]

The question was.. Should you use an analog combo in addition to the Mares puck? I'm assuming the combo has a pressure gauge, depth gauge and a compass. A depth gauge, pressure gauge and TIMER is mandatory whether you use a computer or not. A compass can come in handy. So the answer is yes. If you have 2 high pressure ports, you are good to go - may have a routing issue though and a swivel should solve it. If 1 port, you can buy a splitter. Northeast scuba supply is a good place to start.
. . .

A point I made above was that I think a diver should consider two factors in deciding whether to use an analog console along with an AI puck: the estimated likelihood that the additional analog console will ever be truly needed during a dive to ensure safety, and to what extent the additional analog console and its hose impede streamlining and/or add failure points. Some divers may come to the opposite conclusion from me, but to me, for the type of dives I do, it would be overkill. I don't care to have another hose sticking out and bulky console hanging down and doing nothing but creating water resistance on the, say, 500 dives during which my primary computer works without malfunction. An extra hose in the extra HP port, or maybe a splitter and swivel--these add potential failure points (however unlikely such failures may be).

If the premise is that an AI computer is not very reliable in the first place, why have one? I believe every piece of gear I take along ought to be as reliable on its own as necessary for the kind of diving I do. I have faith that my computer will not malfunction for at least several hundred dives. If something has a seriously high failure rate, I wouldn't dive with it--and I can't imagine the product will be a long-term success for the manufacturer. To me, ascending upon a computer malfunction and maybe foregoing a repetitive dive (and missing the whale shark, beaverdivers) is a small price to pay for not dragging extra stuff along that's unlikely to ever be needed. I believe a redundant analog console (we're not even talking a mini-SPG here, but rather a larger "Combo" or console) is unlike carrying a knife, shears or SMB. Not only are those safety items that may affect your ability to ascend safely, but they can be stowed pretty well out of the way.

The more challenging the dive, the more you may believe the advantages of redundant gear outweigh the disadvantages. It's a personal decision. So I don't believe we can definitively say the answer is "yes" or "no."

Note that I DO advocate a backup wrist computer. See posts above.

 

[scubadada]

Perfect answer! And I will add that I always dive with a watch to time separately. At this point I am either going to use that combo and route it to left side rear d-ring, but I will encounter mounting issue. The left HP port is occupied by my AI computer.

Any recc for routing? I know you mentioned a splitter

Transmitter on the right, HP hose and SPG on the left

---------- Post added July 21st, 2013 at 08:59 AM ----------

I dive an Oceanic VT3 primary with an Oceanic Geo2 and SPG as backup. I've dived this combo for about 3 years and nearly 300 dives. I've not needed the backup to date.

I often dive multiple days, multiple dives per day. To me, the most important reason for backup is to preserve my trip without interuption should my primary computer fail. Though I would continue a single dive should my primary fail, to end one dive prematurely is not as big a deal.

I dive two computers with the same algorithm so that the dive is not always controlled by the more conservative computer. You must always clear the deco on the more conservative computer or you could be locked out and lose the backup. Even after it clears in a day, you'll lose your nitrogen exposure. Prior to my current set, I dived an Oceanic Pro Plus 2 and a Nitek Duo. The Duo was considerably more conservative and controlled all my dives. It was distracting/annoying to always make sure it was clear at the end of the dive when the Oceanic still had NDL time. To be honest, I want the extra time.

As mentioned above, with dual algorithm and conservative factors, a computer like my Geo2 can probably be adjusted to mimick other algorithms reasonably closely. My 1st backup, for an Oceanic Pro Plus, was a Cochran. It's algorithm was a bit more liberal than DSAT, but not much so. The PP controlled my dives.

Good diving, Craig

 

[AfterDark]

OP if it makes you feel safer do it! I dive what I think I need to complete the dive safely. If that's more/less than the next diver is carrying I don't care I'm equipping me not somebody else. If you feel secure in your gear and configuration you will be miles ahead of someone that is diving gear and configurations that are uncomfortable or they have little confidence in. Dive your dives with your choice of gear and configurations you'll enjoy diving more.

 

[nv]

OP if it makes you feel safer do it! I dive what I think I need to complete the dive safely. If that's more/less than the next diver is carrying I don't care I'm equipping me not somebody else. If you feel secure in your gear and configuration you will be miles ahead of someone that is diving gear and configurations that are uncomfortable or they have little confidence in. Dive your dives with your choice of gear and configurations you'll enjoy diving more.

That's a solid response and made me just go with things I am comfortable with. No need for all the bells and whistles @ this time.