Tigerman
Contributor
First off, Ive been working all night (its 8am here in Norway at the moment) so my brains could be playing tricks on me at the moment.
However;
I was just thinking about how were randomly reminded that freshwater and saltwater has a different density, thus apply a different pressure on us while diving. So in a strike of hazy "philosophical mood" I came to think "Does it really matter at all with regards to diving?"
The reason why the thought struck me was that given all other things being equal, if your computer is set to saltwater (or not have the ability to switch) it will show a minor (2,5%?) error in the readings if diving in freshwater as its calibrated for saltwater at 0 feet above sea level, but does this actually affect you in any way while diving?
Your air consumption will increase with pressure and your partial pressures of the gas your breathing will also increase which gives you the whole decompression and narc/tox issues.
However dive computers works by measuring the ambient pressure and the ambient pressure is what trigger all the things we have to observe as divers.
This seems in my tired haze to mean that if your computer shows 100 ft the pressure should be that of 100 ft of saltwater wether its actually 100ft of saltwater or 102,5 (assuming my 2,5% is correct) freshwater you have above you.
As the computer think Im in 100ft of water it will obviously calculate from that and my air consumption should be as if Im in 100ft of saltwater.
Given the above, I should also be able to completely ignore the fact that Im actually slightly deeper if Im in freshwater or is there anything my tired brain is completely missing here?
As far as CESA goes however youd have a couple of feet extra to swim to the surface of course, but thats kinda beyond the scope here as its the physiological and air consumption effects Im thinking about here.
However;
I was just thinking about how were randomly reminded that freshwater and saltwater has a different density, thus apply a different pressure on us while diving. So in a strike of hazy "philosophical mood" I came to think "Does it really matter at all with regards to diving?"
The reason why the thought struck me was that given all other things being equal, if your computer is set to saltwater (or not have the ability to switch) it will show a minor (2,5%?) error in the readings if diving in freshwater as its calibrated for saltwater at 0 feet above sea level, but does this actually affect you in any way while diving?
Your air consumption will increase with pressure and your partial pressures of the gas your breathing will also increase which gives you the whole decompression and narc/tox issues.
However dive computers works by measuring the ambient pressure and the ambient pressure is what trigger all the things we have to observe as divers.
This seems in my tired haze to mean that if your computer shows 100 ft the pressure should be that of 100 ft of saltwater wether its actually 100ft of saltwater or 102,5 (assuming my 2,5% is correct) freshwater you have above you.
As the computer think Im in 100ft of water it will obviously calculate from that and my air consumption should be as if Im in 100ft of saltwater.
Given the above, I should also be able to completely ignore the fact that Im actually slightly deeper if Im in freshwater or is there anything my tired brain is completely missing here?
As far as CESA goes however youd have a couple of feet extra to swim to the surface of course, but thats kinda beyond the scope here as its the physiological and air consumption effects Im thinking about here.
