Diving two computers ?

[Landlocked123]

Given that I am now doing dives mostly in the 110-130 range I am considering purchasing another dive computer as a backup. These are bounce dives on air with very little bottom time - 2-6 minutes (I have very conservative gradient factors set on my petrel) as I am working on a charting project at the local quarry with a handful of dive buddies. I am trying to weigh if it makes sense to invest in another petrel as a backup given we will be pushing NDL limits. These are no deco dives but given the dive profiles I feel this may be a wise investment. Do most people that dive 2 computers dive the same one?

 

[scubadada]

Given that I am now doing dives mostly in the 110-130 range I am considering purchasing another dive computer as a backup. These are bounce dives on air with very little bottom time - 2-6 minutes (I have very conservative gradient factors set on my petrel) as I am working on a charting project at the local quarry with a handful of dive buddies. I am trying to weigh if it makes sense to invest in another petrel as a backup given we will be pushing NDL limits. These are no deco dives but given the dive profiles I feel this may be a wise investment. Do most people that dive 2 computers dive the same one?

It's the easiest thing to do, you will not be able to match computers running different deco algorithms. You could dive a backup that is more liberal than the GFs you are running on your Petrel. What GFs do you run? DSAT often works pretty well, even when running 45/95.

 

[Landlocked123]

45/75...

 

[scubadada]

45/75...

Nearly anything would be more liberal than that, even RGBM

 

[Landlocked123]

Yeah I know very conservative settings... I may go 45/80 ... I had my eyes on an Ix3M. I know it will run Buhlman also so the NDL's should be exactly the same or very close to one another. I could just dive the more conservative one.

 

[RyanT]

If you can afford it, a second Shearwater computer would be ideal. For me, I run a second puck computer in gauge mode and carry a set of pre-cut tables as a back up in the event that shearwater fails. These are for planned deco dives though. If you want to save a bit of money, you could still consider doing something like this and then just run your plan in a dive planning software. I'd be happy to help you with this more if you have any questions.

 

[scubadada]

Yeah I know very conservative settings... I may go 45/80 ... I had my eyes on an Ix3M. I know it will run Buhlman also so the NDL's should be exactly the same or very close to one another. I could just dive the more conservative one.

Ratio runs Buhlmann ZH-L16B, may be a bit different than 16C, I would guess a little more liberal at the same GFs

 

[Landlocked123]

Any experience on Ratio IX3m? I like the size of the screen and brightness. Long story short screen display is a must. We are dropping from 70 to 110 in zero viz through a layer of suspended particulate matter. Hence we built a shotline system and deployed it. Hard bottom at 135 currently. I dont know of too many other options in that category of computer although I heard aqualung came out with a new computer also. Ryan appreciate the help with the deco software but since these are planned no deco not sure how I would use it. Are you saying having tables for 1,2,3, minutes passed NDL scenarios on top of the NDL profile we are diving? We are building 3 minutes of extra NDL time just to sort anything out already.

 

[Landlocked123]

.

 

[Chris H]

Why don't you spend the money on some training and equipment that allow you to spend more than 6 minutes at depth? I have two Petrels, but the 2nd one was a recent purchase. I used a BT and tables as backup for 10+years.