First off - I dive using the metric system so if 700psi isn't quite correct I apologise!
Anyway. I often think that this basic tenent taught in OW - 'back at the surface/on the boat with 50bar' - is fairly nonsensical. Because it takes no account of your tank size it takes no account of the real amount of air that you have left. For example, if I dive a 10ltr tank to 50bar then I have 500ltrs left - but if I dive a 15 ltr tank to 50bar then I have 750ltrs left. Wouldn't it be more sensible to teach new divers how to know exactly what volume of air they have, and need, to make safe ascents and keep safe reserves?
Anyway. I often think that this basic tenent taught in OW - 'back at the surface/on the boat with 50bar' - is fairly nonsensical. Because it takes no account of your tank size it takes no account of the real amount of air that you have left. For example, if I dive a 10ltr tank to 50bar then I have 500ltrs left - but if I dive a 15 ltr tank to 50bar then I have 750ltrs left. Wouldn't it be more sensible to teach new divers how to know exactly what volume of air they have, and need, to make safe ascents and keep safe reserves?