Could high mineral content affect my depth gauge?

[aquacat8]

So I went freediving again today in Warm Mineral Springs, and it occurred to me that I wasn’t in seawater, and I wasn’t in normal freshwater. It’s very high mineral content, the highest of any spring in Florida. Could that affect my depth gauge? It felt effortless to go deeper, although I was very buoyant and wore no weight, and as I’m trying to be super conservative I had to watch it (literally), so that kinda surprised me. So I was wondering... was my gauge affected? Or was it maybe just because I was so relaxed...
warm mineral springs, warm mineral springs, little salt springs, city of north port, sarasota county, sarasota, curt bowen, warm mineral, florida spring, florida
Any other freedivers out there want to try this?

 

[tbone1004]

yes and no

will it affect your gauge in terms of what depth is displayed? yes, unless you tell your computer the density of the medium you are diving in, it will assume it is whatever you told it you were diving in.

will it affect your gauge in terms of decompression calculations if it's a computer? no, the decompression is based on absolute pressure so it doesn't really care if it's fresh, salt, anywhere in between, the dead sea, etc. The number on the gauge may not be the actual linear distance from the surface, but it won't mean much

 

[aquacat8]

Thanks @tbone1004 , it’s actually the linear distance from the surface I was interested in, for freediving. My gauge was telling me I was deeper than it looked or felt like I was. Interesting...

 

[tbone1004]

Thanks @tbone1004 , it’s actually the linear distance from the surface I was interested in, for freediving. My gauge was telling me I was deeper than it looked or felt like I was. Interesting...

IIRC that spring is somewhere around halfway between fresh and salt, so brackish ish density. You'd be about half a foot off per atmosphere

 

[Kharon]

IIRC that spring is somewhere around halfway between fresh and salt, so brackish ish density. You'd be about half a foot off per atmosphere

So - 6 inches in 33 feet. Does that mean that if the computer is set for fresh water and you dive salt (or visa versa) it's only off by a foot at 33 feet?

 

[Bowers]

So - 6 inches in 33 feet. Does that mean that if the computer is set for fresh water and you dive salt (or visa versa) it's only off by a foot at 33 feet?

yes 14.7psi is achieved at 33fsw or 34ffw

 

[tbone1004]

So - 6 inches in 33 feet. Does that mean that if the computer is set for fresh water and you dive salt (or visa versa) it's only off by a foot at 33 feet?

yes, and it doesn't actually matter for your deco calculations, even at 300ft where the difference is pretty substantial because the computer is running the algorithm off of pressure not off of depth.
The EN standard 13319 is about halfway in between so if you are diving both frequently, it's "close enough". It will say you're at 101ft but if you're in fresh you're at 103, or 99 in salt