Underwater off-gassing equivalent to a surface interval on air

[mrtechbench]

I thought the old VR-3 had a continuous ascent mode, but I haven't been able to find a reference to it.

Diver On The Line; Graphics - DELTA P VR3 Operators Manual And Installation Manual [Page 45]

DELTA P VR3 Manual Online: diver on the line, Graphics. The Diver On The Line In This Screen The Variable Ceiling Indicator, (Also Known As The Diver On The Line) Is Displayed. The Indicator Appears Only When You Are Within 3M Of A Decompression Ceiling. It Shows The Proximity Of The...

www.manualslib.com

Yes it does have that, they call it "diver on the line"

...the diver on the Line in this screen the variable ceiling indicator, (also known as the diver on the line) is displayed. The indicator appears only when you are within 3m of a decompression ceiling. It shows the proximity of the next deco stop. When the diver is at the surface the decompression ceiling has been reached. This feature allows you to do a continous decompression rather than a stepped one by ascending slowly and keeping the diver around the middle of the line.The indicator is not displayed when a warning is in force, eg. gas switch, ascent rate or air break...