Vyper Questions

[DivingDoc]

Originally posted by O-ring
Am I the only one that doesn't really look at that graph? On an air dive, I watch the remaining bottom time (displayed as minutes) and follow that. When I got the computer I was a little mystified about the CBT thing too...I figured I didn't need it as long as I knew I was within the NDL based on the numeric bottom time remaining display.

I noticed you are in Richmond...ever dive Lake Rawlings? Let me know if you are up for a trip sometime and we can play with our Vypers

--Eric

So if you are on a multilevel dive, how do you know when to go up to the next level, based on the CBT? I think looking at a nitrogen loading graph and staying in the green would be more intuitive to me. Also, when you are on Nitrox, can you get it to display the actual PO2 level before you get an alarm at 1.4?

 

[DivingDoc]

Here's what Dee says about Suunto vs. Oceanic computers:

Yes, I use a Data Max Pro Plus. My husband used to use a Suunto Vyper. I don't know any specifics about the VersaPro but would expect it lives up to Pelagics reputation.

You've been told right, the Suunto algoritum is more conservative than the Pelagics. You can set the Suunto for 3 (I think) settings but even on the most liberal, it's still more conservative than Pelagics.

We've had a chance to compare the two computers over the last couple of years and they vary quite a bit. We noticed it especially on dive trips where we are diving 3-5 dives a day for a week or more. With my DMPP, the nitrogen would load slowly during the dive. I may have only 2 bars of nitrogen showing and Doug's Vyper is already loaded up and he's being told to take a mandatory stop. As soon as he ascended about 20 ft. the computer would clear and he could drop back down with me. I'm not talking about deep depths either...more like 50-65ft. I would end a 60 minute dive within 3-4 bars of the yellow on my DMPP. His would be clear but only because he had kept ascending 15 to 20ft at various points during the dive. The DMPP cleared during my surface intervals, maybe ending the day with 2-3 bars into the green. Overnight, of course, it cleared.

He recently replaced his Vyper with a Uwatec. It seemed to us that although my DMPP was more liberal, I was doing more consistant dive profiles. Doug wasn't confident in the camputer anymore, mainly because no one could/would explain why the algoritum does what it does!

My opinion from personal use? Go with the Versa Pro. The Suunto has more bells and whistles but they won't help keep you out of the chamber! I trust my DMPP.

Hope this helps.
__________________

Anyone else have this kind of problem with their Suuto's?

 

[Zept]

Originally posted by O-ring
Am I the only one that doesn't really look at that graph? On an air dive, I watch the remaining bottom time (displayed as minutes) and follow that. When I got the computer I was a little mystified about the CBT thing too...I figured I didn't need it as long as I knew I was within the NDL based on the numeric bottom time remaining display.

I feel the same way, O-ring. Why look at the CBT graph and try to figure out what it means when there's a nice big number in the middle of the display that tells you how many minutes you have left?

Originally posted by DivingDoc
So if you are on a multilevel dive, how do you know when to go up to the next level, based on the CBT?

Sorry, I don't really understand your question. Normally I multilevel according to the dive plan I've agreed with my buddy -- if we've planned 18m for 20 min, then 12m for the rest of the dive, that's what we do.

If I were running the dive off the computer, I guess I'd use the remaining bottom time. For example, I might decide that 20min was the limit, so I'd go up a level when that figure was reached (whereupon the remaining bottom time would increase, because I'd be shallower). However, I prefer to plan the dive in advance, so we both know what's happening.

Zept

 

[O-ring]

Normally I multilevel according to the dive plan I've agreed with my buddy -- if we've planned 18m for 20 min, then 12m for the rest of the dive, that's what we do.

Zept, that's kind of what I have done in the past as well. See what there is to see and then move up...IMHO, wouldn't you be pushing the limits and risking a deco obligation (not that deco is necessarily a bad thing) if you are waiting for the CBT to run out at your current depth and then ascending to a shallower depth?

The left side bar graph switches between O2 and N2 depending on which one has the greatest impact and will switch from one to the other during a dive if the loading becomes a limiting factor.

As far as it switching over, maybe it does with your Stinger, but my Vyper doesn't. I just ran a test dive on mine to 130 feet in nitrox mode using EANx21. The bar on the side stayed on OLF and never switched to nitrogen loading even when I passed the NDL as displayed by the minutes remaining.

I ran the same dive in air mode and it stayed on the CBT display (as I expected) throughout the dive. I guess I don't see the point...the CBT graph just seems to me like a graphical representation of the same information the remaining bottom time display gives. The deeper I went, the higher that graph went and it hit the red as soon as I passed the NDL for 130 ft.

Looks like you get OLF (oxygen limit fraction = oxygen exposure) displays for nitrox mode and CBT (consumed bottom time = nitrogen loading/exposure) displays for the air modes and that's pretty much the way it works...

--Eric

 

[Zept]

Originally posted by O-ring
IMHO, wouldn't you be pushing the limits and risking a deco obligation (not that deco is necessarily a bad thing) if you are waiting for the CBT to run out at your current depth and then ascending to a shallower depth?

I wouldn't let the bottom time run out. That'd be a bad idea, as you say. However, I've done dives where the divemaster has said, 'Keep an eye on the remaining bottom time, don't let it get below 20 minutes, start moving up when it gets close to 20 minutes.' Using this approach, you always have at least 20 minutes of bottom time remaining at your current depth, so you aren't pushing the limits.

I'm not endorsing this approach, just reporting on it.


Zept

 

[O-ring]

Problem solved!!!

Use the remaining bottom time for your NDL information on air dives and your DSAT oxygen exposure table for your nitrox dives and tape over the offending display!

Ok, maybe a little extreme, but IMHO it is more useful as an OLF display than a CBT display since it is redundant with the remaining bottom time display (which is in nice big numbers that even I can see).

 

[Lost Yooper]

for those interested, the Vyper won't let you bend it, surface, and then throw it back in the water so it can finish it's deco like the old Aladin Pro's would. I tried it last weekend. It locked up before I even reached the surface.

Mike

 

[DivingDoc]

Originally posted by Lost Yooper
for those interested, the Vyper won't let you bend it, surface, and then throw it back in the water so it can finish it's deco like the old Aladin Pro's would. I tried it last weekend. It locked up before I even reached the surface.

Mike

Not sure what you mean by a computer getting "bent." I know what it is for a person getting bent, but not for a computer getting bent. Can you explain further?

 

[O-ring]

I think Lost Yooper means throwing the computer into ERROR mode by violating the algorithm and then "tricking" it by lowering it on a line back to 15 feet or so and letting it finish its deco by itself so you can use the computer later. Some won't let you dive for 24-48 hours or so after an ERROR mode (lockout).

 

[Lost Yooper]

Yeah, that's right. They scream at ya for a little bit, then die .

Mike