Cobra 2 100% vs 50% RGBM setting

[Codeman00]

ajduplessis: I did go back and re-read your posts. I didn't not read it the first time, it just seemed like everyone had a different few on the 50% RGBM and I wasn't sure if anyone actually knew what the difference was. I actually think my Deco time was more like 10 minutes or so then added a safety stop on top of that. So I guess it was about 15 minutes when it was all said and done...I have the download cable on order...Once I load it to Dive Manager, I'll have a better idea of the exact time. All I know I was suprised that "I" let myself get into Deco because it's not something that I ever thought would happen to me. But it did. Maybe I was in major danger but after reading numerous threads about different dive computers, it looks like the Suunto is extremely more conservative than my Mom's Oceanic...and I'm only looking at a single dive, not multiple dive days for multiple days. Some divers even dive with a Suunto and a less conservative computer at the same time just for reference and to have a backup.

Either way, I'm going to try Nitrox for my upcoming trip and see how that goes. I'll also watch my ascents, etc....although I don't think that's an issue with me.

 

[ajduplessis]

There are little differences between Oceanic and Suunto with regards to single dive NDL's. Please go back and check both personal and altitude settings (should have been A0 & P0). There is no way they could have been such big differences. Saw tooth profiles are also not good for NDL values. I would love to get a copy of your profiles once you have downloaded them.

 

[Scuba Duner]

After 22 posts, my original question remains a mystery. How does the 50% and 100% settings for the RGBM affect a dive? We may never know.....

 

[BoltSnap]

After 22 posts, my original question remains a mystery. How does the 50% and 100% settings for the RGBM affect a dive? We may never know.....

Why not ask this question in the Aqua Lung Forum?

 

[ajduplessis]

Choosing the 50% RGMB model means that the computer only applies HALF of the penalty to subsequent dives, giving you slightly longer bottom times. Penalties include fast ascent rates and short SI.

 

[Codeman00]

ajduplessis: I will get my cable here in a few days but it might be a 2 weeks or so before I can send them to you due to me going on vacation soon. That would be great if you could look at them and tell me what you think....it sounds like I could learn something from this. I appreciate the help.

 

[daz88]

my last trip to Oahu I did 28 dives in 7 days while using my Suunto. And only hit "deco" time once. And that was after a 100+ dive with a pretty short SI, then a 60' dive. (so figured it might happen)
All week, the 1st dives of the day were 100'+, 2nd dives were about 60'. Afternoon dives about 40'. I was always the 1st diver in the water and almost everytime the last diver out. Not sure what type computers the other divers where using or where they were at, I just know my Suunto only hit deco one time, and figured it might coz I was the last one back on the boat and only had about a 15-20 SI. check your ascent rates, maybe that's why your computer is cutting down your time on the second dive.

 

[divin'dog]

I dove a Vytec 2 for a while... I used the 50% setting. I noticed that if you ascend too quickly (even waving your arm up and down), it will be "shorten" your dive. Most of the times, I was within most divers using other brands of computers but when it wasn't, it was a pain in the arse because while other divers were still diving, I was doing a safety stop for a few extra minutes. I ended up selling it and getting something else (for that and other reasons). Now I'm a happy diver and still diving within NDL's. If you continue using the Suunto, be careful when ascending even for a couple of feet and try not to do sawtooth type diving. You need to do a smooth profile.

 

[greatlakeswreckdiver]

I agree with divin' dog. My wife was certified before we met and I later got certified. When looking for equipment, I decided on Suunto so we were diving the same algorithms. Got Nitrox certified in Florida on a boat that primarily dove Nitrox 32-34%..at 60-70' dives every day. I found more benefits with diving Nitrox than just more bottom time, I felt I had more energy after a 2 tank dive. (not looking to start a flame war over the after affects of Nitrox...as stated, this is what benefit I feel...)

So with that said, I dive wrecks in the great lakes. Most of the time in the 70 - 120' range. When diving air with others running other computers, mine is definitely more conservative diving a very similar profile on air just as the other diver is. I am thinking about switching to Nitrox 30% for these dives to give me more safety factor without tricking my computer. It cost a little more, but when I set my Vytec to 50%, I really didn't see any difference. It did make a big difference when my profiles became more smooth and my ascents slower but still doesn't give me as much bottom time on repetitive dives over 80'.

Another trick I did was put the Vytec into Nitrox 21% and played with the PO2 setting. Again - no major differences. I have been on dive boats that have said, "If you go into deco, you will sit out the next dive". They would go around after each dive and check your computer. As soon as they saw my wife and I diving Suunto...they kept an extra close eye on our computers by checking history and everything. All the locals were diving Oceanic. By day 2 I was ready to switch to gauge mode and run my charts rather than let it go into deco...

 

[Codeman00]

I am back from my trip to Turks & Caicos where I dove 5 days... I had originally planned diving 2 tanks Monday through Wednesday and the do the 3 tank boat trip on Thursday. As I posted above, I wanted to make sure that my Suunto Cobra 2 gave me as much bottom time to keep up with my wife who was diving with an Oceanic. I got some advice from some people on the board that my main problem is probably my saw tooth profile and the fact that I dive until the last possible minute and do my safety sop as quick as the compuer lets me before I surface. In other words...right when I hit 550-600 psi, I will head up quickly to my 15 ft safety stop and then surface. This time, I tried to slowly move up to my safety stops. But I also decided to dive Nitrox too to see if that would actually even me up with my wife. So I did dive EAN 32 all week.

As far as the first 3 days go, my Nitrox was my limiting factor on each and every dive, not my nitrogen level. My wife was diving air and she only had a couple of times she was in the yellow...but all and all, me diving Nitorx and her diving air evened us out. That shows how conservative the Suunto really is. And yes, I did watch my ascents closely and came up slower than ever before.

Thursday we didn't end up doing the 3 tank...that was going to be a big test just to see what would happened to her bottom time and my bottom time. Oh well, I dove Nitrox and had the same results as Day 1 through 3. Then came Saturday...it had been more than 24 hrs since we dove...basically a clean slate. The Nitrox compressor was down so we had to dive air that day....it would be interesting to see how that affected my bottom time. During the descent on the first dive, my wife was above me having some issues, so I violated my safety stop going up immediately to check on her. I knew that was going penalize me bad. So we finally corrected the problem and I went through the entire first dive...to about 85 max and used my entire tank of air. On the second dive though, I wasn't so lucky...even on the wall, I could see my bottom time become limited....after checking my wife's computer, she had plenty of minutes left. I watched my computer like a hawk and as we dove through the 55 ft shallows...my bottom time finally got down to 1 and then just for a second into Deco....with plenty of air left.. So there I went up to do my safety stop about 15 minutes ahead of if I would have been diving Nitrox. I left my wife to tool around on the bottom with her Oceanic while diving air....while I waited for her. About 15 minutes later, she came up and her computer was in the yellow.

There is a big difference between Suunto and Oceanic.