If you feel fine at the beginning of the dive but begin to experience this on your ascent, try descending a little bit and trying to clear your ears again. Sometimes one of the equalizing techniques used on descent will clear your ears on ascent. Pointing the affected ear toward the bottom may help, too. Ascend as slowly as your air supply allows. Increasing pressure usually opens the Eustachian tube and relieves overpressure. However, in rare cases it may persist all the way up. In that case, you will have to endure the pain to reach the surface. Notify your buddy, and stay in close proximity.

First aid: Nasal decongestant spray may help open the Eustachian tube and relieve the reverse squeeze. A physician evaluation is advised if you experience vertigo, protracted pain and fullness of the ears.