Calem's Atmo Sphere

From complete immersion within water at or near sea level, or watery mud or quicksand, or other mostly-water solutions, you conjure up a sphere of breathable air at sea level pressure, with a 5-foot radius that completely encompasses your head and upper torso. The bubble-like sphere remains for the spell’s duration or until dispelled and moves with the caster, staying fixed in place relative to where it was initially manifested on their body.

While the spell is active, casters that are normally air-breathing may breathe the air within the bubble and speak or cast any spell typically cast while on dry land. The spell is good for up to one hundred feet of depth below sea level. To compensate for additional depth, it can be cast at higher levels to grant an additional one hundred feet of depth per level cast, or additional 5ft diameter, at the caster's option, at standard depth.

Once the spell elapses or is dispelled, the bubble sphere collapses into a cloud of bubbles that travel in the path of the least resistance, leaving the caster once-more completely immersed in the fluid they cast the spell into.