Analog Depth Gauge Accuracy

[Rick Vigil]

I'm in the process of upgrading my analog depth gauge and am wondering if some designs are inherently more accurate than others. I understand that many brands are manufactured by a single company but with different face inserts for different brands.

One popular option seems to be the analog depth gauges manufactured by Pelagic (recently acquired by Aqualung) which have a non-linear scale where the needle moves more at shallower depths. It appears that the Aqualung, Oceanic, Sherwood, Genesis, Tusa, and XS Scuba depth gauges are all made by Pelagic. Are these all the same in quality and accuracy, or does Pelagic do more than just change the face insert to differentiate the brands?

Then there are several other options that have a linear scale where the needle moves the same amount independent of depth. Some appear to be made by the same manufacturer but with different branding, like the Zeagle, Highland, and Apeks but others do not, like Cressi, Suunto, Scubapro, and Oceanics' "oil filled" gauge. Are any of these inherently more accurate than the others, or more accurate than the non-linear Pelagic ones?

I also have an old capillary depth gauge from the 70's. Is it's simple design inherently more accurate than the analog needle ones?

On the one hand, I prefer the ones with a non-linear scale as I'm a recreational diver and my main use of the gauge would be to hold a 15 ft safety stop if my dive computer dies and I thumb the dive, and the 15 ft level is much easier to read on those. On the other hand, if the linear scale gauges are more accurate, that would be safer in that my safety stop would be closer to 15 ft.

Thanks ahead of time,

Rick

 

[BoltSnap]

Why not a dive computer or a digital bottom timer?

 

[tbone1004]

your capillary gauge is going to be the most accurate in the shallows because it's not a spring, but the readability is determined by how long it is so pros and cons. Analog depth gauges are all going to be "close enough", but if you want the most accurate, just get a cheap computer. The digital pressure sensors in there are going to be incredibly accurate, even on the cheapies.

I think the Deep6 should be out by the end of the second quarter if you can wait that long and will be around $150 IIRC

 

[ripman3]

You got to love scubaboard. What analog gauge is better?

Why not a dive computer or a digital bottom timer?

 

[BoltSnap]

You got to love scubaboard. What analog gauge is better?

And your problem is???

 

[Altamira]

I certainly am not answering for ripman3, but I suspect he was pointing out the same thing I noticed that frequently occurs on this board.
1. Answering a question that was not asked.
2. The responder does not read the entire original post before commenting. In this case, Rick Vigil clearly stated, the analog depth gauge was used primarily to hold a safety stop depth in the event his computer dies.

 

[tbone1004]

I certainly am not answering for ripman3, but I suspect he was pointing out the same thing I noticed that frequently occurs on this board.
1. Answering a question that was not asked.
2. The responder does not read the entire original post before commenting. In this case, Rick Vigil clearly stated, the analog depth gauge was used primarily to hold a safety stop depth in the event his computer dies.

1. he did answer the question. The digital sensors are going to be more accurate than the analog ones and not that much more expensive with the added benefit of being a backup computer
2. even if he did read the full post, the answer probably would have been the same. You're going to spend $50-$100 on a new analog depth gauge. They're cheap, but not terribly accurate with most only being accurate to +5ft.

Vs.
Used Dive Rite Duo Computer with Green Case
$100, with a DSS bungee mount, user replaceable batteries, does decompression, etc etc. Fits in most consoles, and will actually do backup computer duty for you. Will be accurate to within +1ft. So here you have a more versatile device, and the most accurate gauge.

Now, the capillary gauge is the answer to the title which specifies analog gauge, especially at shallow depths, but it can flood, isn't accurate the deeper you go, and can be hard to read

 

[BoltSnap]

So if the OP is asking the wrong questions for the wrong conclusions, we continue the same?

The OP wants the Analog depth gauge to do the following:

my main use of the gauge would be to hold a 15 ft safety stop if my dive computer dies and I thumb the dive

The best and appropriate answer for his "quest" is either a backup computer or a digital bottom time not an analog gauge. Per @tbone1004 's answer above, it doesn't make any sense to use Analog depth gauge of any kind at all. To actually to go out and seek to buy an analog gauge in today's market, is a waste of money and effort.



BTW, I have used "capillary gauges" many decades ago and they are terrible for anything that requires even remote amount of accuracy or practicality. They are difficult to read underwater and would need constant cleaning of their tube. The tube gets discolored because of dirt and fungus inside the tube.

 

[emoreira]

I'm carrying in each dive my PDC, the analog depth gauge in the console and a Citizen Aqualand dive watch. I guess enough redundancy related to depth measurement. For my security stop at the end of each dive, I've found that the PDC has enough accuracy, which in turn depends of your buoyancy to keep that depth during that stop.
How accurate needs to be a depth gauge to measure depth for a security stop (no deco stop, as the OP says he is a recreational diver) ?
Lets go to the Open Water Diver courses where it is stated that the security stop should be done at a depth between 3 to 5 meters for 3 to 5 minutes. The range is huge enough to allow standard depth gauges fit for the task.

 

[dberry]

Not to toss gasoline on the fire, but 15ft isn't a magic number for a *safety stop*. Isn't it enough to know you're somewhere between 10 and 20 ft, assuming your analog gauge is constant?