Backup Computer went into Deco

[kelemvor]

Cressi Leonardo supports deep stops. I bet you have it configured to do deep stops and missed one. The resultant deco was probably a missed stop penalty.

English manual here: https://www.cressi.com/easyUp/file/instructions/IB_LEONARDO_EN.pdf See page 22 for deep stop information.

Edit: Nope. The manual goes on to say it simply recalculates the dive if the diver misses a deep stop as if it were not configured to do a deep stop in the first place.

 

[Tbar]

I agree, also being that the AI computer knew my SAC doesn't it also give credit for nitrogen intake?

May need to do a refresh on decompression theory, nitrogen at ~80% of air is predominate in the body irrespective or breathing rate.

We did go deep, max depth was 118fsw for 3 minutes, then 60 feet for the majority from there.

You were in freshwater? Was it 118fsw or ffw? Where both computers on same setting, salt or fresh? I don't expect it would account for the variation but if there setting are different you can expect divergence.

If you plan to dive with a back-up computer you need to check both, the is no value if the back-up is in deco or locked-out, and probably dive the more conservative computer. Saying this the Cressi probably is a poor option for a back-up computer.

 

[Lorenzoid]

You were in freshwater? Was it 118fsw or ffw? Where both computers on same setting, salt or fresh? I don't expect it would account for the variation but if there setting are different you can expect divergence.

The only difference the freshwater versus saltwater setting makes is in the depths it displays. A computer that computes a 44 min. stop at "15" ft. in saltwater is just going to compute the same 44 min. stop a few feet deeper in freshwater, because the relevant input to the deco algorithm is measured pressure, not depth.

I think the computer malfunctioned.

 

[dmaziuk]

Saying this the Cressi probably is a poor option for a back-up computer.

Mares Icon also runs some sort of RGBM so they shouldn't be that different. Mostly you'd see this sort of thing if you're diving EAN and forgot to tell that to your backup, but I strongly doubt you can get 44 minutes of deco after a 34-minute dive that way. If legit, this suggest a computer failure rather than operator failure.

 

[uncfnp]

Not to mention that on a first dive the Cressi RGBM tends toward "liberal." But if in SF 2 that can be very restrictive... Agree with @gfaith, I would like to know the settings.

 

[Tbar]

The only difference the freshwater versus saltwater setting makes is in the depths it displays. A computer that computes a 44 min. stop at "15" ft. in saltwater is just going to compute the same 44 min. stop a few feet deeper in freshwater, because the relevant input to the deco algorithm is measured pressure, not depth.

Agreed, the point stated was if they are set differently then there will be more variation in the computers. "if there setting are different you can expect divergence."

 

[scubadada]

Of course, this report makes little sense. Were you diving nitrox, were both computers set for the correct mix? Mares and Cressi both utilize relatively conservative RGBM algorithms, Cressi perhaps a bit more conservative. Were the conservative settings approximately equal? Perhaps the Cressi pressure/depth sensor is incorrect?

 

[AdivingBel]

Hope you bought your buddies several rounds that evening...

 

[runsongas]

what does the cressi have your max depth and time logged as? does it match the mares roughly?

 

[Centrals]

I also dive with two computers of different brands and the conservative one is the one that I follow.