Out of Air and All By Yourself

Controlled Emergency Swimming Ascent
Controlled Emergency Swimming Ascent

The Controlled Emergency Swimming Ascent (C.E.S.A) skill trains you to an unlikely out of air emergency event where you cannot reach your buddy for help. Mastering the Controlled Emergency Swimming Ascent is an important stem into becoming a more confident skilled scuba diver.

learning Controlled Emergency Swimming Ascent

Controlled Emergency Swimming Ascent skill objectives

Where to practice Controlled Emergency Swimming Ascent

How to master Controlled Emergency Swimming Ascent

Controlled Emergency Swimming Ascent Tips

Why learning Controlled Emergency Swimming Ascent

It’s very unlikely you’ll ever need to perform a Controlled Emergency Swimming Ascent in real life, but it’s wise to know how to handle running out of air completely by yourself. If you ever ran out of air, and your buddy’s too far to reach, or nowhere to be found, this would be your best option for ascending slowly to the surface.  Find more out of air solutions here

Controlled Emergency Swimming Ascent Objectives:

Simulate a controlled emergency swimming ascent (CESA) by swimming horizontally underwater for at least 9 metres/30 feet while continuously exhaling by emitting a continuous sound.

Where to Controlled Emergency Swimming Ascent?

You’ll practice C.E.S.A twice during your open water course. Initially, during the confined water session, you’ll practice in relatively shallow water, though to deep to stand in. this session is conducted horizontally, swimming for about 9m/30ft on one breath. Later, during one of the last 3 dives of the open water course, you’ll practice the skill vertically. You’ll have to prove you can ascend slowly on one breath of air from 6-9m/20-30ft

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How to complete and perform the Controlled Emergency Swimming Ascent?

Horizontal skill:

1. Achieve neutral buoyancy (Fin Pivot or Hovering)

2. Inhale Deeply.

3. Give your Instructor “Out of Air” sign

4. “Superman position”- Right hand stretched over the head, left hand hold the deflator hose simulating a controlled ascend.

5. Regulator stays in your mouth for the entire skill. This prevents water from entering your mouth, even if accidentally trying to inhale. On a real event, when ascending to the surface, you may have some air left in the tank expanding due to reduced pressure, meaning you may have one more breath to inhale as you move closer to the surface.

6. Swim slowly (same as ascent rate) making a continuous AHHHH sound for a minimum 9m/30ft.

Vertical Skill (Open Water Dive):

1. There’s no need for neutral buoyancy as your heading to the surface.

2-5 are similar as above.

6. Slowly (18m/60ft per minute) ascend to the surface making a continuous AHHHHH sound.

7. As you ascend, deflate your BCD if achieving positive buoyancy.

8. At the surface, Orally inflate your BCD to achieve positive buoyancy, simulating an out of air emergency.

Controlled Emergency Swimming Ascent tips

1. Practice on-land, making sure you understand the steps. This skill is a bit tricky to follow underwater.

2. Time yourself. Check how long you can exhale for. You can then calculate the depth you may perform that skill comfortably (remember 1ft per sec). Bear in mind that as we ascend air expands in our lungs. You feel like you have more air than you though you do.

3. On the controlled emergency swimming ascent skill, after achieving Neutral Buoyancy, add a little bit more air to your BCD. As you empty your lungs, you become less buoyant and may otherwise end up brushing the bottom. 4. On the vertical controlled emergency swimming ascent skill, your instructor will hold you and anchor himself to a line. Do not use that line, it’s simply there to slow or stop you if you ascent to fast.

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