SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/scuba-cesa-emergency-ascent

Out of air with no buddy near and the surface close, divers learn which emergency skill?

CESA: Controlled Emergency Swimming Ascent.

Start playing free

  1. A fast breath-hold sprint
  2. Buddy breathing with a fish
  3. A Controlled Emergency Swimming Ascent (CESA) ✔

Why: In a CESA the diver swims slowly up while exhaling the whole way, letting expanding air out of the lungs. It is practiced in the Open Water course with an instructor.

Huh, didn't know that: Instructors teach CESA on a secured vertical line so they can stop the ascent at any time.

The dad joke
Why did the scuba diver hum all the way up? It was a CESA-nade.
Like this card?
Play the game

References

Answer: A Controlled Emergency Swimming Ascent (CESA). In a CESA the diver swims slowly up while exhaling the whole way, letting expanding air out of the lungs. It is practiced in the Open Water course with an instructor.

  1. PADI Pros: Conducting CESA pros-blog.padi.com/conducting-cesa
    The Controlled Emergency Swimming Ascent (CESA) is one of the most complex skills in the Open Water Diver course.
    Checked 2026-10-12.
  2. DAN: Emergency Ascents, Managing the Risks dan.org/alert-diver/article/emergency-ascents-managing-the-risks
    If you cannot reach your buddy or another diver, or if your buddy is also out of air, complete a controlled emergency ascent on your own.
    Checked 2026-10-12.

Think this answer is wrong? Tap "Challenge this answer" on the card in the game and tell us why.

Test yourself in the game

Sports & FitnessYou run out of air and your buddy is close by. What is your first move?Sports & FitnessHow does a diver signal out of air?Sports & FitnessWhat is the first rule of scuba diving?

That's stuff everyone should know.