What is a synonym for "air level"?

Common synonyms include: atmospheric layer.

Air level

noun

noun ·Rare ·Advanced level

Noun

1
A spirit level. dated
2
Used other than figuratively or idiomatically: see air, level.
"When diving, take care to monitor not just your air level, but that of your partner."

"When diving, take care to monitor not just your air level, but that of your partner."