baffled by Suunto D4i info while diving vs dive log

[eab]

You need to keep eyes on your D4i display more often than your UWATEC SmartCom, especially when you are close to NDL. When you see D10 (Deco obligation at 10 feet ceiling depth) displaying on the screen with how long you need to be at that depth, that means you just pass NDL. It’s time to ascend. As you ascend slowly (> 30 ft/min), the D10 time would slowly decrease down to zero and even disappear if you keep ascending. At that point you can resume your diving at that shallower depth.

If you feel that it’s so conservative and much different than your UWATEC SmartCom, assuming your D4i’ RGBM algorithm setting is like my D4, then change it from RGBM 100 to 50, as shown in page 39, section 5.8.9 of the D4 manual, below

https://ns.suunto.com/Manuals/D4/Userguides/Suunto_D4_users_guide_EN.pdf

View attachment 721203

@Dan - Coming back to this .... my D4i doesn't have the option to adjust the RGBM value. I can only change the sample rate timing -- 10, 20, 30, or 60 seconds.

 

[eab]

US$60.00 for Uwatec battery replacement is not too bad.
DIY for Suunto.

I am never happy with RGBM algorithm. Conservatism is not a big issue, it is the idiosyncratic way with so many "safety" criteria to obey.
You will not be able to buy another brand new Uwatec computer. However, your present one should last at least several more yrs. You can tell if the computer is near the end of it's life when the display gets dimmer ie. difficult to read.

If you have spare cash then an invest it on obsolete Oceanic Voe 2. It has dual algorithms(PZ+ and DSAT) and the former could be similar to RGBM. The DSAT is too liberal.

Thanks! I baby my Uwatec so much that the plastic cover is barely scratched. Still had the original nub that covered the hose opening until the DM 3 trips ago put it in his pocket never to be seen again. The nub, of course, although I did debate him as well.

 

[dmaziuk]

So true! I was fighting with a leaky mask one dive and it was yellow triangles all over. The dive was about 25 feet max and maybe 40 minutes, and the dive log looked hilarious!

Computers make very fast very accurate misteaks

 

[scubadada]

@Dan - Coming back to this .... my D4i doesn't have the option to adjust the RGBM value...

You appear to be correct, the D4i does not seem to have the ability to change to 50% RGBM from the normal 100%. You can only make sure that you are on personal adjustment 0. the least conservative. The computer runs regular Suunto RGBM, moderate on the 1st dive, often more conservative on repetitive dives due to penalties (SI, ascent rate, profile...)

Your Smart Com runs Buhlman ZHL-8 ADT, generally moderate to conservative. Make sure you are running at setting L0, least conservative.

Always run your computers at the nitrox percentage that you are using, none of this air stuff.

You obviously missed a deco stop on your Suunto on the dive you describe and went into violation gauge mode, or worse, no function. I have never dived a Suunto. You will have to monitor both computers, satisfy any deco obligation to avoid the lock out. Both of these computers are moderate to conservative, I would not worry too much about approaching NDL or satisfying short deco obligations. Of course, this brings up gas planning and making sure you have plenty of gas to complete your dive. As a divemaster/instructor, these things should be perfectly obvious to you.

 

[Centrals]

https://ns.suunto.com/Manuals/D4i/Userguides/Suunto_D4i_UserGuide_EN.pdf

p15
Ascent rate
Continue ascent rate violations result mandatory safety stops!
Be careful if you use the corrugated hose to dump gas ie do not raise it abruptly.

p/26
Omit decompression stops for more than 3 mins the computer is locked for 48hrs.
Personal adjustment setting at 0 is the only option to make D4i less conservative.

 

[Dan]

@Dan - Coming back to this .... my D4i doesn't have the option to adjust the RGBM value. I can only change the sample rate timing -- 10, 20, 30, or 60 seconds.

Looks like @scubadada & @Centrals answered your question. My D4 is really old, I bought it back in 2013.

 

[eab]

You appear to be correct, the D4i does not seem to have the ability to change to 50% RGBM from the normal 100%. You can only make sure that you are on personal adjustment 0. the least conservative. The computer runs regular Suunto RGBM, moderate on the 1st dive, often more conservative on repetitive dives due to penalties (SI, ascent rate, profile...)

Your Smart Com runs Buhlman ZHL-8 ADT, generally moderate to conservative. Make sure you are running at setting L0, least conservative.

Always run your computers at the nitrox percentage that you are using, none of this air stuff.

You obviously missed a deco stop on your Suunto on the dive you describe and went into violation gauge mode, or worse, no function. I have never dived a Suunto. You will have to monitor both computers, satisfy any deco obligation to avoid the lock out. Both of these computers are moderate to conservative, I would not worry too much about approaching NDL or satisfying short deco obligations. Of course, this brings up gas planning and making sure you have plenty of gas to complete your dive. As a divemaster/instructor, these things should be perfectly obvious to you.

Thanks.

I haven't been low on air since I hit double digit dives. My friends tease me that I'm a mermaid. Running out of NDL is more my problem.

Yes, once I downloaded and analyzed the dives in the Suunto DM5, I could see the error. All in hindsight of course. Must have missed it on the display during the dive, and my Uwatec was just happily computing without any concern. That's the one I check throughout. Now I know I should check the Suunto as well. Lesson learned, thankfully without any grave circumstances.

 

[eab]

https://ns.suunto.com/Manuals/D4i/Userguides/Suunto_D4i_UserGuide_EN.pdf

p15
Ascent rate
Continue ascent rate violations result mandatory safety stops!
Be careful if you use the corrugated hose to dump gas ie do not raise it abruptly.

p/26
Omit decompression stops for more than 3 mins the computer is locked for 48hrs.
Personal adjustment setting at 0 is the only option to make D4i less conservative.

Oddly, I have started using the valve on my right shoulder instead. Just something that came to me. Good to know that was a wise insight. Thanks!

All adjustable settings have been reviewed side by side with the manuals posted here. The one I have has barely any photos and was tough to follow. These others were more visual, more my style. I'm all for Ikea-style directions.

 

[eab]

Looks like @scubadada & @Centrals answered your question. My D4 is really old, I bought it back in 2013.

Mine has also received a software upgrade since I got it maybe a year ago.

I appreciate you trying and sharing the info. Even the discussion has kept my wheels turning....

 

[eab]

After having Uwatec SmartCom, SUUNTO D4 & Shearwater Teric, I highly recommend anyone to get Shearwater Teric!

I finally checked out the Teric. The page loads with a "as low as $1,150" Plus another $400 for the air integrated transmitter. Ouch. Maybe someday.

But it certainly does look like a sweet computer!