depth gauge verse computer ?

[hudson_hawk]

hello heres a question /
i just got my open water certifcation
my last dive i had that day was a short dive sence i didnt have enough air
for longer one
we went over and down a rock wall
i was informed the depth was about 50 ft down the wall
i was useing a older computer a uwantic sport it read a max depth of 50 ft
i all so had the analog gauge
the computer was showing about 63% battery left
now i question is , my analog gauge said i was at 60 ft deep
lol i know its only ego but which one does every one think was wright
im kinda hoping it was the analog one i did go lower then the rest
well what does every one think
btw the gauge was a new suunto depth/spg
thank all

 

[Damselfish]

If I had to guess, I'd pick the new gauges over an old computer. But if the max depth was really 50ft and you didn't take a shovel, well things can go wrong with new gear too. Who knows? But as I'm sure you well know, it's not about going deeper than anyone else and it just doesn't matter as far as that goes. What does matter is that if any of this is your gear, you compare it against a couple others and see which one is wrong, or get it checked out by the shop. If it was rented, you might have mentioned it to the shop that something is obviously wrong with one of them.

During the dive, if you've got 2 different readings like that, you should check against your buddies gauges or the instructors to see which of yours has the correct depth. It might even be good to check at a few different depths.

 

[ScubaSixString]

hello heres a question /
i just got my open water certifcation
my last dive i had that day was a short dive sence i didnt have enough air
for longer one
we went over and down a rock wall
i was informed the depth was about 50 ft down the wall
i was useing a older computer a uwantic sport it read a max depth of 50 ft
i all so had the analog gauge
the computer was showing about 63% battery left
now i question is , my analog gauge said i was at 60 ft deep
lol i know its only ego but which one does every one think was wright
im kinda hoping it was the analog one i did go lower then the rest
well what does every one think
btw the gauge was a new suunto depth/spg
thank all

Was the SPG/Guage on a long hose? and if so was it dangling? that could account for SOME difference. But another question that comes to mind is what type of water were you diving? If it was fresh and your guage was set for salt, that would make a diffence to. it would read shallower.

 

[ScubaSixString]

hello heres a question /
i just got my open water certifcation
my last dive i had that day was a short dive sence i didnt have enough air
for longer one
we went over and down a rock wall
i was informed the depth was about 50 ft down the wall
i was useing a older computer a uwantic sport it read a max depth of 50 ft
i all so had the analog gauge
the computer was showing about 63% battery left
now i question is , my analog gauge said i was at 60 ft deep
lol i know its only ego but which one does every one think was wright
im kinda hoping it was the analog one i did go lower then the rest
well what does every one think
btw the gauge was a new suunto depth/spg
thank all

They let you use a computer?

My things HAVE changed. I remember *violins play* the good old days (1995) when they wouldn't let you use one

"Residual Nitrogen Time?!!! What the hell does that mean???????" lol

 

[hudson_hawk]

hello all again
well it was fresh water botom temp was 51 deg
it was a normal hose and it was cliped to my bcd
one thing they hammered home never let any thing dangle
if it was on a reef it would cause damage to it
the depth was for my ego i admite i just love diving thanks again all

 

[ScubaSixString]

hello all again
well it was fresh water botom temp was 51 deg
it was a normal hose and it was cliped to my bcd
one thing they hammered home never let any thing dangle
if it was on a reef it would cause damage to it
the depth was for my ego i admite i just love diving thanks again all

a saltwater guage or computer (some let you adjust this) will read shallow (i think) in freshwater. This might account for some of the difference.

BTW, worry less about your depth. Lots of folks have gotten hurt trying to prove their diving prowess by going deep. Diving is great. Its even better if you're around to enjoy it

 

[hudson_hawk]

thank you scuba six
and yes safty first as all ways
have a good day and thank you

 

[MrConclusion]

FYI - The depth reading conversion going from fresh to salt water is about 3%, depending on the salinity of the salt water in question.

I remember hearing that many Uwatecs until very recently were factory calibrated for fresh water. If this is true for yours, then showing 50ft in the ocean might mean you're actually at 48.5ft.

Why the discrepancy? Because salt water is heavier than fresh, and depth gauges are basically measuring the weight of the water above you.

Mechanical depth gauges versus electronic ones in dive computers? Hard to say - anything can be miscalibrated or lose calibration. In my experience (which is MUCH more limited than others) is that mechanichal gauges are more subject to being "slightly wrong" due to impact damage, wear, etc., while computers are more prone to being "absurdly wrong" due to electronic problems.

Last week, in a 60ft max depth quarry, a student's (2 month old) rental computer console logged his dive at over 200 feet, and then was beeping like crazy at him to make decompression stops on the way up after a 20 minute dive!

 

[Mlody11]

Why the discrepancy? Because salt water is heavier than fresh, and depth gauges are basically measuring the weight of the water above you.

QUOTE]

True. What does it matter anyway to callibrate it? The effects on your body are not at what depth you are... but what kind of pressure you are under. Correct? Maybe we got this whole thing with depth wrong ... maybe we should be measuring the pressure instead . Its all the same if you think about it but that way you dont need to mess with the calibration.

 

[mossym]

Why the discrepancy? Because salt water is heavier than fresh, and depth gauges are basically measuring the weight of the water above you.

QUOTE]

True. What does it matter anyway to callibrate it? The effects on your body are not at what depth you are... but what kind of pressure you are under. Correct? Maybe we got this whole thing with depth wrong ... maybe we should be measuring the pressure instead . Its all the same if you think about it but that way you dont need to mess with the calibration.

if it's not giving the correct information it doesn't matter what it's calibrated to..