Computer + Plan or 2 Computers for Deco Diving

[rjack321]

This is how I dive. If I've cut my tables right, it shouldn't be too different from what the computer spits out. I like to pull up the shearwater generated schedule at my first stop and compare it to my wetnotes to make sure they're aligned. If there are meaningful multi level segments (P3 comes to mind), those are factored in to the tables. Average depth usually works though.

If we're down a computer, I'd compare the schedule on the working computer to the tables and (gas volume permitting) go with the more conservative (more deco) schedule if they're reasonably close. If they differ significantly, try to determine why (shallower average depth, shorter BT, etc) and go with the one that makes more sense. If I can't determine why, go with the more conservative schedule. Either way, deco out as a team. 99% of the time, a bit of extra deco won't hurt you.

I was trained a long time ago - PS (pre-shearwater lol)
I consider my buddy's computer/depth gauge to be my backup. I consider his/her brain as a backup to mine.
I would go with the schedule that makes the most sense. This would likely be recalculating my table plan (assuming it didn't already account for what we've done up until the point of failure) based on a shallower than max depth and seeing how that matches the remaining computer. I would expect my buddy to hang with me even if his/her computer had cleared a stop. The further away our obligations are from one another (for whatever reason) the MORE we need to stick together since things are already going sideways.

Last summer I ended up doing almost 25 extra minutes of deco with a buddy due to his computer problem - so our 95 min runtime dive got extended up at 120mins. Fortunately I wasn't on OC. If I had been, the time glitch never would have happened as it was a CCR specific issue I think.

 

[helodriver87]

I was trained a long time ago - PS (pre-shearwater lol)
I consider my buddy's computer/depth gauge to be my backup. I consider his/her brain as a backup to mine.
I would go with the schedule that makes the most sense. This would likely be recalculating my table plan (assuming it didn't already account for what we've done up until the point of failure) based on a shallower than max depth and seeing how that matches the remaining computer. I would expect my buddy to hang with me even if his/her computer had cleared a stop. The further away our obligations are from one another (for whatever reason) the MORE we need to stick together since things are already going sideways.

Last summer I ended up doing almost 25 extra minutes of deco with a buddy due to his computer problem - so our 95 min runtime dive got extended up at 120mins. Fortunately I wasn't on OC. If I had been, the time glitch never would have happened as it was a CCR specific issue I think.

Yeah, if you're truly diving as a team (same plan, gradient factors, gases, etc) their computer is as good as your computer. Pick the logical schedule based on available information, stick together, share resources, and you're good. I don't really see a compelling reason for a second computer if you're diving that way.

 

[Bigbella]

In the past, when bottom timers were cheap, and computers were expensive, it made lots of sense to run bottom timers and cut tables. Now, you can get used Shearwaters for the same price as a bottom timer. Technical diving isn't a poor man's game, if you can't afford $400 for a used Shearwater, you realistically can't afford to be a technical diver.

That doesn't mean all of that's useless, and I carry backup tables in my wet notes on every dive in case I screwed the pooch and screwed up my gases or something, I can always use depth and time to safely ascend.

Agreed. In the old days, it was strictly dive tables and watches, even before the electronic bottom timers; and we were none the worse for them (everyone that I dove with decades ago, can still feel their extremities); but, with the advent of cheaper computers, just carry two -- and keep that old watch; tables; slate, and SPG functioning as well . . .

 

[stretchthepenn]

Just curious about this scenario. If you only had one shearwater (each). Plus your table plan. Your shearwater dies (say dead battery) but your buddy is right there and has been at most ~8-10ft away the entire dive. Do you:

give yourself credit a multilevel dive and follow his shearwater?
both revert to a square table plan (assuming its not a multilevel plan on the slate) and he sits there and watches you finish?
split up and he leaves you in the dust while you finish the square plan?

Hrm... Good question; you're making me think. Based on past performance, and assuming the entire computer conks out, leaving not even a bottom timer, I think we'd abort the dive and surface together according to the table plan.

 

[sabbe]

I started #1 until I could afford #2. I'm glad I learned option #1 while training.
Don't cheap out the 2nd computer, get matching brand computers (same user interface, not necessarily same model) I screwed something up more often than not when I had 1 - Hollis TX1 and 1 - Shearwater Perdix.
Currently experimenting with different Shearwater display setup on each wrist so I get twice the info at a glance.

When I added 2nd Shearwater I stopped writing tables, but I've started writing again as I think it helps planning with my current buddy who learned planning a little differently than I.

If we're warm & comfortable we'll follow tables; if we're cold we'll follow the computer.

Wrist slate easier/faster to use with thick gloves where I do most my diving.

 

[lermontov]

I don't really see a compelling reason for a second computer if you're diving that way.

looks more tech in photos

 

[lermontov]

I was trained a long time ago - PS (pre-shearwater lol)
I consider my buddy's computer/depth gauge to be my backup. I consider his/her brain as a backup to mine.
I would go with the schedule that makes the most sense. This would likely be recalculating my table plan (assuming it didn't already account for what we've done up until the point of failure) based on a shallower than max depth and seeing how that matches the remaining computer. I would expect my buddy to hang with me even if his/her computer had cleared a stop. The further away our obligations are from one another (for whatever reason) the MORE we need to stick together since things are already going sideways.

Last summer I ended up doing almost 25 extra minutes of deco with a buddy due to his computer problem - so our 95 min runtime dive got extended up at 120mins. Fortunately I wasn't on OC. If I had been, the time glitch never would have happened as it was a CCR specific issue I think.

this is how i was instructed - diver last to clear controls the dive ( in regard to deco stops) however that presupposes your diving same profile and G/f - it shouldn't be too much difference 2-3 minutes maybe if theres more then something has gone astray -regardless I stay with my buddy until we both are clear - tropical water no problem cold water im not so happy

on an aside even with a DC dieing in theory if your monitoring you will have a reasonable idea of times to make an informed decision and if your slate info was adequate youll know if your +/_ the written schedule