GAP Software

[ScubaMartin]

Anyone knows if tables output by Gap are for Salt or fresh water?

Thanks!

 

[padiscubapro]

Anyone knows if tables output by Gap are for Salt or fresh water?

Thanks!

When in Metric it calculates based on the European Standard, (based on a specific temp and specific gravity of the water but msw would be close)
When Imperial it uses the US navy defination based on a specific temp and specific gravity, again fsw would be close)

All water varies depending on mineral contenet.. so there is really no such thing as a standard fresh water or salt water.. So its more correctly stated fett or meters of water based on whatever unit standard you are using..

Most modern dive computers sold use these definitions if they want to be able to be sold in the EU.. if they dont use the standard definitions they are supposed to state this..

 

[ScubaMartin]

My question was more to discuss about the following. I' ve got a D3 Suunto ans a Uwatec bottom timer. The uwatec is calibrated for fresh water and the suunto for salt water. On fresh water deeper dive, say 206 feet, the uwatec will display 206 and the suunto 200 since salt water is ~3% denser. If I output a table for a 200 feet dive and I use my suunto, at 200 feet I will be actually at 206 feet in fresh water. In conclusion I should I've used my 210 feet bail-out table....And overshoot the depth. This could be a problem...

Any comment?

When in Metric it calculates based on the European Standard, (based on a specific temp and specific gravity of the water but msw would be close)
When Imperial it uses the US navy defination based on a specific temp and specific gravity, again fsw would be close)

All water varies depending on mineral contenet.. so there is really no such thing as a standard fresh water or salt water.. So its more correctly stated fett or meters of water based on whatever unit standard you are using..

Most modern dive computers sold use these definitions if they want to be able to be sold in the EU.. if they dont use the standard definitions they are supposed to state this..

 

[padiscubapro]

My question was more to discuss about the following. I' ve got a D3 Suunto ans a Uwatec bottom timer. The uwatec is calibrated for fresh water and the suunto for salt water. On fresh water deeper dive, say 206 feet, the uwatec will display 206 and the suunto 200 since salt water is ~3% denser. If I output a table for a 200 feet dive and I use my suunto, at 200 feet I will be actually at 206 feet in fresh water. In conclusion I should I've used my 210 feet bail-out table....And overshoot the depth. This could be a problem... @3000 feet altitude is already over a 3ft difference, a 6000ft its about 7 feet

Any comment?

pressure is pressure.. depth in dive planning software is not a linear measurement its a pressure measurement.. use the 200 fsw tables and keep in mind the proper conversions about 3 feet per 100 feet or about 1 foot per ata, in case the sw (well sw somehwere) guage fails.
if you planned a dive to 206 FFw and 200 fsw the plans would be the same (or pretty dam close due to slight differences in stop depths)

a reading off 200 fsw (in the carribean) isnt the same as 200 fsw in the north east, salinity content is different.. the linear measurement to the surface (ACTUAL DEPTH) is different..


planning it for the fresh water reading does you no good since if the fww guage fails and you try and run it by the sw water guage your stop depths are wrong.

if you were following a computer you would have to make sure you used THAT to determine where you are supposed to stop.

What can be even a BIGGER issue is how your computer dealswith altitude.. is the computer's "depth" measurement an absolute pressure rating or is it surface adjusted..

some computers/guages are absolute, what that means is that you are actually deeper (linear to the surface) than the guage reads when you are altitude.. if its surface adjusted is pressure from the surface..