My buddy and I are planning a shore dive. We’re descending onto a very gradual slope that begins at 5 metres/15 feet, so our descent and ascent will be a gradual part of swimming out and back underwater. We have similar cylinders filled to 200 bar/3000 psi.
We plan:
50 bar/500 psi reserve.
20 bar/300 psi for our safety stop.
To turn the dive when we’ve used one-third of the air available
to use on the dive.
This means we should head back when either of our SPGs read: