Citizen Cyber Aqualand

I want to know if anyone has any experience with the Citizen Cyber Aqualand Nx dive watch. My wife bought me the watch as a Christmas present and I have several dives on it without really paying too much attention to the dive log. A couple weeks ago I did a dive mainly in 40 - 50 fsw but went off the edge of the reef into 67 fsw for about 5 minutes. My dive computer prior to ascent was well within NDL, much more than 10% under if memory serves. Bottom time was about 50 min at time ascent started. When I checked the watch after the dive the log indicated that I had done a DECO dive meaning I had exceeded the nodecompression limits according to the watch. OK, my Padi tables say 70 for 40 for the first dive but I spent most of my time 50 or less and the NDL for 50 is 80. It seems the watch does not act as a dive computer in the sense of repeatedly measuring depth and time against tissue gas models to produce an accurate profile, it just measures max depth and total bottom time and runs its functions against standard tables. I am not complaining since I don’t use the watch as a dive computer and it certainly is more than conservative. However, nothing in the promotional material or manual indicate that this is nothing more than a glorified bottom timer with built in tables. So it seems that if you want a nice dive watch, this one is nice. If you are looking for a dive computer, this it is not. Am I missing something?

—Bob

Well I spent some time looking at this watch online at Citizen.com and also working through their online manuals and pretty decent "live" mode here http://watch.citizen.co.jp/cyber-nx/fl_eng/main_f.htm.

Are you saying that you think this watch may only calculate NDL's based on a square profile like the PADI tables and not like the wheel with multiple level dives? After some time researching, I found no proof that this is or isn't the case. If it is the case, then this thing stinks. Who wants a computer that doesn't calculate at multiple depths,lol. I just couldn't imagine that this is the case as this was originally a $900 toy when it came out but hey, Citizen is a watch company and not a dive company so it is possible. However, they do call it a dive watch computer on their web page. Moreover, I wouldn't think that they would add a Deco calculation function to a dive computer that assumes square profiles. That could be really dangerous. This computer also calculates nitrox dives. It appears to be a full featured dive computer like you said.

Edited after more research:

http://www.scubaboard.com/showthread.php?t=13585&highlight=cyber+aqualand

This thread will answer the question. It seems the answer is that it is using a dif. and somewhat more conservative set of tables. The DCIEM algorithm was developed by the Canadian Military for strenuous cold-water exposures from what I have found out so far.

Here is a review of this watch that may also help http://www.zerovisibility.co.uk/Aqualand.htm

Bob,
I haven't had any problems with my Aqualand Nx other than when I've let the
battery run down. It is not a square profile dive computer, it uses the DCIEM
"Canadian" decompression calculation. Did you download your dive profile on a
computer and it indicated a violation? What specifically was displayed that
alarmed you? Typically the computer will beep and flash in the display during
your dive that you have exceeded your NDL time, then you will get the information
for required stops. Another possibility is a faulty or dirty water sensor.
Let us know what you find.

First of all, I want to thank all of you for the information. I was not sure where to start looking.

As a second point, I am not unhappy with Citizen or the watch. I have owned Citizen dive watches for over 20 yrs and I have been happy with all, including this one.

I fairness to Citizen, I do not intend to use this watch as a dive computer. I am nearsighted and have a prescription mask which makes it difficult to read the fine data on the display during a dive. My only curiosity is why the watch said I did a decompression dive when I take pains to avoid decompression diving.

I do not have the attachment to upload data to my computer and it does not have an IR input (I guess I could buy one that plugs into a usb port). I did go back to review the watch log info. It says my first dive on 5/14 was max 67 ft for 47 min. My dive time did include a slow ascent and a 3 min safety stop so I figure I left the bottom about 40 or 41 min into the dive. My max depth was 67' and average depth was 51'. The small graph in the watch shows my dip to 67 toward the end of the dive. My dive computer agreed with the watch as to time and depth. It told me I was within my no decompression limits. The watch log, however, has the word DECO in the lower left hand side of the display which, according to the manual, means I did a decompression dive. I do not recall hearing the watch alarm.

My dive buddy, Jeff, was using 32 EAN and dives a nitrox computer so he was not of much help. My computer is an early model ORCA Marathon which is why I give it a lenient margin of error. My dive buddy, Lee, uses a datamax which I have checked against the Marathon. It is more conservative but well within my 10% rule on the Orca.

Perhaps I was premature in suggesting that the Citizen uses a “square profile” but its model seems to be more conservative than any computer I have seen. I still believe that this is a nifty dive watch but not a substitute for a dedicated dive computer.

—Bob

If your average depth was 51feet and your max depth was 67feet and your BT was 47min. and your watch is conservative (according to the above link) then that could = a deco dive according to your watch. An average depth of 51feet and a dip down to 67feet at the end of the dive supports this thinking. Add to that, your buddy was diving nitrox so he was no help as you said...it is possible that according to your possibly conservative watch, you did a deco dive. The dive profile is even close using PADI tables, the wheel, and my computer with your average depth of 51ft and that dip to 67 at the end. You also mentioned that you don't pay much attention to the watch because you are using a computer and that you can't see the numbers on your watch very well and that doesn't bode well for seeing your watches deco warnings if they really went off in the first place of course. As for hearing the warnings, I never knew if my watch was beeping underwater especially when using a hood. Just some thoughts.

I used to own a titanium citizen with basic bottom time features and I also liked it a lot but I sold it because it was just too big and heavy to be warn for everyday use in my humble opinion.

I appreciate the comments and insight Scubadobadoo. I actually went and dusted off my PADI air RDP tables. The square profile would be 70 for 40. Since I started the ascent no later than 42 min and my max depth was 67 ft I violated (by a smidgen) the square profile. However at 50' I had a NDL of 80 min and at 60' the PADI conservative 55'. So my actual dive profile should have been well within NDL as shown by my Marathon. This is what caused me to question whether the watch was using a square profile. Now I don't know much about the DCIEM algorithm, but it seems to approach the square profile in conservatism.

Thanks again for the links and the info and your interest in helping me figure this out.

---Bob

ScubaBOBuba:

I appreciate the comments and insight Scubadobadoo. I actually went and dusted off my PADI air RDP tables. The square profile would be 70 for 40. Since I started the ascent no later than 42 min and my max depth was 67 ft I violated (by a smidgen) the square profile. However at 50' I had a NDL of 80 min and at 60' the PADI conservative 55'. So my actual dive profile should have been well within NDL as shown by my Marathon. This is what caused me to question whether the watch was using a square profile. Now I don't know much about the DCIEM algorithm, but it seems to approach the square profile in conservatism.

Thanks again for the links and the info and your interest in helping me figure this out.

---Bob

Click to expand...

I don't claim to know the Cyber Aqualand. I dive with the Hyper Aqualand, and love it!

The HA does not have dive planning features (and is not Nx). It's functionality is in keeping a record of my dives and a backup to my dive computer (if something happens to the dive computer, I can use this watch with the tables and keep diving).

The real functional use for this watch is downloading all dives to my computer for safe keeping and profile observation. It allows me to keep a computerized dive log, and even creates .html pages for internet posting.

I have not posted any .html pages... give me a few minutes and I will have an example up for you... brb

If you were diving Nitrox, you have to tell the watch what % your O2 is.

Hope that helps.

I personally love the watch. When I make a leap to a full blown computer I'll keep it as a back up.

Here is the example... It took extra time. The first one did not show all of the features for the html, so I went back and added some information so you could see all of the things it will post.

Click Here