looking for recommendations on a dive computer

[Dan Thoms]

yup..... (one day, until then i still use Bills)

$$$-

[Randy Thornton]

I've been using a Vytec ever since they came out. I have over 500 dives on my original unit. Never even replaced the batteries! My only complaint about it at all is that it does not do Trimix. I use a VR3 for that.

The Vytec is pretty much bullet proof, light weight, and the deco model works fine for me for non-trimix dives.

[Gary]

The Vytec is pretty much bullet proof, light weight, and the deco model works fine for me for non-trimix dives.

I noticed some of the Suunto computers had a crazy safety stop thing where you just did a long safety stop at 20' and when you get to 15' it stops you and starts a safety stop counter. Does the Vytec have that also or can you turn it off?

[Alan Garrett]

I'll admit I haven't really done my homework on this one, but if I wanted to use a Vytek with Helium (normoxic), couldn't I just go ahead and do deep stops according to V-planner, offgas the Helium, and then switch to the Vytek schedule for the longer stops? I think the Vytek uses RGBM as well and it seems to me the two would play well together if used conservatively. But then again maybe I should avoid all the extra b.s. and just spring for a real tri-mix computer since it looks like I'll need to eventually anyway. I just like all the good reports I've been hearing about the Vytek and didn't want to dismiss it without some fair consideration.

[firehawk335]

Just took my adv. Nitrox/Deco back in May. I've had my VR3 a little over a year now and had it for the class. My instructor (very very good instructor) didn't mind that I had my VR3 on but I still had to plan my deco tables and dive the tables. So a bottom timer/depth guage is all you'll need for the class. He gave me this example... He once had a student in a trimix class with a new high-end computer and there were 3 students and the instructor; they had planned tables and were diving tables but on the ascent the student with the new computer started watching his computer for deco stops rather than running the tables so 2 students were proceeding to shallower stops while 1 was performing deep stops and the instructor is stuck in the middle trying to take care of everyone. Bottom line, you and your buddy need to either run the same deco computers or run tables; and you won't need the deco computer for the class as it will be taught off of tables unless you have some prearrangement with your instructor.

-Chip

[Alan Garrett]

Well, the Nitrox/Deco thing is already behind me so I'm already familiar with running off tables, but some of the local profiles and run-times can get a little hard to plan precisely, at least in my experience. I just think it would be nice to have an extremely capable computer to help stay on track in real-time. The fellow I cave dive with most often uses an HS Explorer and he has had good luck with it, and I know at least two others who feel the same way. I'm thinking seriously about that one too. I'm not diving in "Helium territory" yet, but I know I'm going to have to soon if I'm going to see much new cave around here and I'm trying to avoid wasting money on something that won't be much use to me a year or so down the road. It's possible that the Vytek may fall into that category (sad to say). Also, good download software is important to me too since that's mostly how I log my dives. Maybe I'd better let it go for now and go pester somebody else for a while!

[Gary]

I'll admit I haven't really done my homework on this one, but if I wanted to use a Vytek with Helium (normoxic), couldn't I just go ahead and do deep stops according to V-planner, offgas the Helium, and then switch to the Vytek schedule for the longer stops?

You could.

As a set of thumbrules for when I'm doing trimix and using my nitrox computers (Bheulmann) for backup I do the following:
Set O2% to O2% + 1/2 He%
do deepstops by table (-2atm from avg depth do 1 min stops up til the first longer stop)

from there if my tables were to be lost I generally find my nitrox computer would do the remainder of the deco if I double the depth of each stop the computer requires (shifting up 10' towards for later half of that stopdepth).

Usually I find these thumbrules put me only a few minutes off where I should be and gives me a feel-good computerized backup to diving tables.


If you just programmed normoxic and didn't modify the computer stops deeper I imagine the stops wouldn't match between your tables and computer til the 10'/20' stop. If you then stayed for the time for your computer to clear you would probably find that a much longer and more conservative deco. I think that was an issue many complained about diving the Nitek He and the VR3 at the same time was the amount of extra deco the He would require if you dragged it thru the VR3/table deepstops.


I don't know what kind of stop depths you might get off the Vytec RGBM implementation but I would guess you'd probably find the thumbrules above would fairly closely match even for the Vytec. (However if you computer will lock up on CNS O2 toxicity you won' be able to set to O2 + 1/2He without it erroring out - fortunately my Bridge just beeps and flashes the O2 bar but keeps going).

[aw]

He gave me this example... He once had a student in a trimix class with a new high-end computer and there were 3 students and the instructor; they had planned tables and were diving tables but on the ascent the student with the new computer started watching his computer for deco stops rather than running the tables so 2 students were proceeding to shallower stops while 1 was performing deep stops and the instructor is stuck in the middle trying to take care of everyone.

-Chip

Not sure I understand this. I've dove with buddies diving VR3's and me on an He. I don't recall if I've been with anyone diving tables other than as backups. Could have. We've done mix dives to 287'. Although one might stay at a stop 10 ft deeper for a few extra minutes, it wasn't a problem. You could see them. No one ever was more than 10 ft higher at any given time. The deeper stops is more to control a SLOW ascent to the 50 ft and shallower range where you do longer stops. So there really shouldn't be that big a gap.

Another issue you get into is people diving different mixes. We'd do a deep dive and someone would be comfortable with a more narcotic mix, but I would try to hit the best mix formula. And they'd prefer a third deco gas. I'd end up sitting at 10 ft for 20 minutes more than them. They'd sit on the surface and wait. We just had an understanding that we'd each follow our own schedules.

Yet another issue is lost gas. What if one diver had lost O2 or 32% or 50% or whatever, that person's gonna be in the water a LOT longer than you.

I've found that tables and computers are not that much off from each other, when I'd cut tables as backups. The benefit of the computer is adjusting for the actual dive profile, a dive cut real short, or extended due to problems.

[Alan Garrett]

I'll admit I haven't really done my homework on this one, but if I wanted to use a Vytek with Helium (normoxic), couldn't I just go ahead and do deep stops according to V-planner, offgas the Helium, and then switch to the Vytek schedule for the longer stops?

You could.

As a set of thumbrules for when I'm doing trimix and using my nitrox computers (Bheulmann) for backup I do the following:
Set O2% to O2% + 1/2 He%
do deepstops by table (-2atm from avg depth do 1 min stops up til the first longer stop)

from there if my tables were to be lost I generally find my nitrox computer would do the remainder of the deco if I double the depth of each stop the computer requires (shifting up 10' towards for later half of that stopdepth).

Usually I find these thumbrules put me only a few minutes off where I should be and gives me a feel-good computerized backup to diving tables.


If you just programmed normoxic and didn't modify the computer stops deeper I imagine the stops wouldn't match between your tables and computer til the 10'/20' stop. If you then stayed for the time for your computer to clear you would probably find that a much longer and more conservative deco. I think that was an issue many complained about diving the Nitek He and the VR3 at the same time was the amount of extra deco the He would require if you dragged it thru the VR3/table deepstops.


I don't know what kind of stop depths you might get off the Vytec RGBM implementation but I would guess you'd probably find the thumbrules above would fairly closely match even for the Vytec. (However if you computer will lock up on CNS O2 toxicity you won' be able to set to O2 + 1/2He without it erroring out - fortunately my Bridge just beeps and flashes the O2 bar but keeps going).

I may have to look hard at doing that then. I just checked the prices on the HS trimix computers and got my feelings hurt!

[Randy Thornton]

The Vytec is pretty much bullet proof, light weight, and the deco model works fine for me for non-trimix dives.

I noticed some of the Suunto computers had a crazy safety stop thing where you just did a long safety stop at 20' and when you get to 15' it stops you and starts a safety stop counter. Does the Vytec have that also or can you turn it off?

I don't think there is a way to turn off the safety stop feature. Or if there is a way, I have never seen it. I don't mind too much however, because the way I look at it, I am just adding an extra 3 mins. on my last stop. I don't mind doing the extra time.