Nevertheless, the fact remains that the basic pressure unit was developed using a ratio of a depth (1 meter of fresh water) to an arbitrary unit (1). It needed to be adapted to work for salt water.They used fresh water to create the "feet of salt water" unit? That makes no sense.
You feel the same pressure at 30.5 meters depth in salt water that you would feel at 30.7 meters of depth in fresh water.Following your conclusion, if I'm under 100 feet of salt water, I feel a pressure of 100fsw. Let's see, you say that 100 feet are 30,5 meters and 100fsw are 30,7msw, right?
Almost right. You feel the pressure of 30.7 mfw.So I'm diving at a depth of 30,5 meters and I feel a pressure of 30,7msw?
Yes. It is necessary to adjust for the density regardless of whether you are measuring your depth in feet or meters.I know saltwater is denser than freshwater and that our depth gauges measure pressure, which are displayed as depth.
fsw is an abbreviation for feet sea water, msw is an abbreviaton for meters sea water.
Youre right, I do have a serious mental block with regards to why fsw->msw takes into account a liquid that is not present.
If I dive a freshwater calibrated gauge in seawater, I can see why I need to add ~2,5% depth to whats displayed, but that would be applicable both to feet and meters?