Sag75, thanks for your reply. I ran the test again and you are right, pressing 'e' and 's' makes a difference (maybe I tested it at non-zero speed
).
I also tried the 'Press twice' trick again and it works. Just press 'e' and watch the compressed air dial. When it stops then press it again (don't press 'e' again while the dial is still moving). Be sure that you do not give any other 'depth command' in between.
Using GWX, I found the following (0 knots, VIIB, 142m (ordered 150m)):
'e': over 4 min. to reach the surface
'e'-wait-'e': less than 2 min. to reach the surface. The compressed air goes down continuously until you reach the surface.
Cheers, LGN1