Per Bob F:
If a big bubvble surrounds you, you are only going down. Lots of little bubbles,
still down. Bubbles in a pipe may carry thing up, but there is no pipe in this
circumstance.

Every bubble means that much less water floating you.

Long, long ago and far, far away part of my misspent youth involved
surfing fairly large waves.

My experience was that the best thing to do while you're in the white
stuff underwater is to relax as completely as possible to conserve air
and swim for the surface only after the white stuff has passed - because
there just is not enough buoyancy or purchase in the white stuff.
--
Pete Cresswell