Level 1 Freediver

Question 1

What is air?

Answer 1

78% Nitrogen, 21% Oxygen, Remaining 1% CO2 and other gases

Question 2

Explain how we breathe in?

Answer 2

The diaphragm and intercostal muscles contract enlarging the thoracic cavity creating a negative pressure and sucking air into the lungs.

Question 3

Explain the passage of air into the body

Answer 3

The air flows through the mouth, nose, and glottis, down the trachea then separates between the left and right bronchi.

The bronchi separate further into a number of bronchioles which lead to alveolar sacs

In the alveolar sacs there are clusters of alveoli which are wrapped in blood vessels and it is here where gas exchange takes place.

Question 4

Briefly describe gas exchange?

Answer 4

Oxygen in the inhaled air diffuses into the blood and is exchanged for Carbon Dioxide.

Question 5

Explain how and what we exhale

Answer 5

The carbon dioxide (about 5%), along with unused oxygen (about 16%), nitrogen (78%) and other gases (1%) is then exhaled as the diaphragm relaxes and the cycle repeats.

Question 6

Explain Diffusion

Answer 6

Diffusion in the lungs is the exchange of Oxygen (O2) and Carbon Dioxide (CO2) between the alveoli and the blood.

Blood flowing into the capillaries in the lungs has a low concentration of O2 and a high concentration of CO2

In the alveoli there is a high concentration of O2 and low concentration of CO2.

Therefore the 2 gases exchange across the alveoli membrane by diffusion trying to establish a concentration gradient

Question 7

What triggers the urge to breathe?

Answer 7

A build up of Carbon Dioxide triggers the urge to breathe.

NOT A LACK OF OXYGEN

Question 8

Explain the process of gas exchange in detail

Answer 8

The diffused oxygen bonds primarily to the hemoglobin molecules in the red blood cells of the blood.

The heart then pumps this oxygenated blood around the body via the circulatory system

As oxygen is used by the body, CO2 is produced

When CO2 levels increase, breathing is stimulated

The CO2 is transported in the blood back to the lungs to be exhaled.

Question 9

What is Apnea?

Answer 9

Holding our breath

Question 10

List 4 ways the urge to breathe is manifested by increased CO2 levels

Answer 10

1. A feeling of tension
2. A burning sensation around the lungs and diaphragm
3. A need to swallow
4. Involuntary contractions of the diaphragm

Question 11

When we experience the urge to breathe, especially in the early stages, what has likely occured?

Answer 11

A build up of CO2, not necessarily a lack of O2

Question 12

What is the Mammalian Dive Reflex? How is it triggered?

Answer 12

Humans, along with other mammals, are equipped with the Mammalian Dive Reflex (MDR), which helps the body conserve oxygen when submerged under water

The Mammalian Diver Reflex is triggered by:
1) The face being exposed to cool water
2) Hypoxia (low oxygen)
3) Increased pressure

Question 13

What 2 dive related physical changes to the body will this course cover?

Answer 13

Peripheral Vasoconstriction and Bradycardia

Question 14

Describe Peripheral Vasoconstriction

Answer 14

During apnea, peripheral chemoreceptors detect lowers levels of arterial oxygen which causes blood vessels int he arms and legs to constrict.

As a result less oxygen is used by the extremities and more oxygen is available to the vital organs and the brain.

Changes in pressure can further enhance Peripheral Vasoconstriction

Question 15

Describe Bradycardia

Answer 15

Bradycardia is the slowing of the heart rate

It is strongly linked to Peripheral Vasoconstriction and further enhanced when a person’s face is submerge in cool water.

It is particularly helpful to free divers as the slowing heart rate helps to conserve O2 on longer dives.

Question 16

What are the two primary goals of breathing for freediving?

Answer 16

Relaxation and Oxygenation

Question 17

What is diaphragmatic breathing and how do you do it?

Answer 17

Involves contracting and relaxing the diaphragm.

To perform:
1) Lie on your back with your legs extended and your arms by your side or upright with your arms resting by your thighs

2) Begin breathing normally, but concentrate on keeping the muscles in your chest and shoulders completely relaxed.

3) Focus on isolating your abdomen and using our diaphragm to drive the breathing process.

4) Try to avoid pushing out the abdomen too much.

Question 18

Describe the process of chest breathing?

Answer 18

Once you have mastered diaphragmatic breathing, add chest breathing to the breathing cycle

Continue your diaphragmatic breathing cycle, but when you have inhaled the full amount of air the diaphragm alone can suck in, use the muscles in the chest to expand the ribcage in order to inhale more air.

Focus on remaining relaxed when doing this

When exhaling relax the muscles in the chest and allow the chest and rib cage to return to a neutral, relaxed state

Do not use the muscles in the chest to force the air out of the lungs

Continue exhaling by relaxing the diaphragm

Question 19

Describe the process of upper body breathing?

Answer 19

As you inhale using your diaphragm first and then your chest, finally add the motion of raising your shoulders and slightly tilting your head back to inhale the last bit of air(The motion is similar to raising your shoulders when sighing).

Briefly hold your breath and return the shoulders and neck to a relaxed position.

Exhale once again by allowing the relaxation of chest muscles to push the air out of the lungs

Relax the diaphragm and allow more air to be exhaled

Question 20

What is triangular breathing ? When is it used?

Answer 20

Triangular breathing is a rhythmic breathing technique which helps induce bradycardia (lowering of heart rate), aids muscular relaxation and decreases blood pressure.

Used to lower the heart rate in preparation for apnea.

Question 21

How do you perform triangular breathing?

Answer 21

Lie on your back with your legs extended and your arms by your sides and sit upright with your arms resting on your thighs

Begin breathing by using a combination of diaphragmatic and chest breathing.

Concentrate on being relaxed.

Do not inhale or exhale to maximum capacity if this creates tension.

Instead inhale and exhale a little less air and make sure that your muscles are relaxed.

When you are comfortable and ready to begin slowly inhale and count the seconds as you breathe in

When you have fully inhaled pause for a few seconds and then begin to slowly breathe out. Count the seconds.

Try to breathe out for twice as long as you breathe in.

Continue in this rhythm and increase the times, if it gets uncomfortable decrease the time back.

Once you have found a relaxed rhythm maintain it for 10 cycles

Question 22

Describe the final breath before free diving

Answer 22

The last breath before freediving should be used to inhale the maximum amount of air that the lungs will allow.

Fully exhale, using the muscles of the chest and abdomen to force out as much air as possible without creating too much tension

Then inhale to the maximum filling the lungs, first using the abdomen, then the chest and finally the upper body.

Question 23

Why is recovery breathing important?

Answer 23

To safely replenish the depleted O2 in the body

Question 23

How is recovery breathing performed?

Answer 23

Partially exhale the air in the lungs and then immediately inhale more air with a brief pause at the top of the inhale.

Repeat the recovery breathing several times in quick succession before resuming a natural breathing rhythm

Question 24

What should you never do immediately after surfacing from a dive?

Answer 24

Never exhale fully immediately after surfacing from a dive

Question 25

What is hypoxia?

Answer 25

A state where our oxygen levels have decreased significantly

Question 26

What are some signs of hypoxia?

Answer 26

Pale or blue skin and blue lips

Question 27

If oxygen levels continue to drop after mild hypoxia what two things can happen? What are these mechanisms trying to achieve?

Answer 27

Loss of Motor Control (LMC) Loss of Consciousness (LOC) These are the body's way of automatically restarting the breathing process

Question 28

Describe an LMC

Answer 28

Severe hypoxia can trigger seizures which typically involve uncontrollable muscle twitches. These can be confined to only one part of the body like an arm or affect the whole body. Also known as a Samba because the twitching resembles a Samba dance. Is usually followed by a state of confusion or unresponsiveness It usually lasts only for a few seconds and if the the free diver starts breathing again the condition could disappear quickly. However in some cases an LMC can lead to blackout even if breathing resumed.

Question 29

Describe a Blackout

Answer 29

Is a loss of consciousness triggered by severe hypoxia. IF oxygen levels drop to a point where the brain can no longer function normally the brain will shut down and enter a state of unconsciousness. Can follow an LMC or occur without warning.

Question 30

Describe an Ascent Hypoxia Blackout?

Answer 30

Also referred to as a shallow water blackout (SWB) Is a blackout that occurs in the ascent phase of a free dive, typically in the last 10m from the surface. It is caused by latent hypoxia and major pressure changes.

Question 31

What is hyperventilation? Why is it dangerous?

Answer 31

Is the act of breathing too much Removes CO2 but does not add much oxygen. Therefore it delays the urge to a point that is beyond safe resulting in a high risk of blackout with little or no warning.

Question 32

Aside from delaying the urge to breathe why else is hyperventilation disadvantageous?

Answer 32

Increases heart which increases O2 consumption Can cause tensing of muscles counter productive to relaxation technique Can strengthen the bond between haemoglobin and O2 making it harder for the O2 to be released to the tissue

Question 33

List 6 things we can do to make our own free dives safer?

Answer 33

1) Adpot a slow and gradual approach to increasing free diving dpeth and apnea times. Establish limits in a safe controlled manner. 2) Learn to identify the symptoms of hypoxia including: confusion, tunnel vision and the feeling the dive is getting easier. 3) Avoid hyperventilation 4) Use recovery breathing after dives 5) Do not dive when stressed or ill 6) Use freediving equipment that is in good working condition.

Question 34

What must we be able to do when observing a dive buddy? and vice versa

Answer 34

Observe symptoms of an LMC or a BO and be able to deal with these situations safely

Question 35

List 8 signs or symptoms that indicate and oncoming LMC or BO

Answer 35

1) A sudden increase in speed or stiffness in movement 2) Body tremors, including shaking limbs or nodding head 3) Uncoordinated movements 4) Loss of direction 5) Grabbing the dive line 6) Blue lips or pale face 7) Exhaling air 8) Confusion

Question 35

What to do if your dive buddy experiences an LMC?

Answer 35

1) Gently take hold of your buddy and keep his/her airways out of the water 2) If any facial equipment is hampering recovery then remove it 3) Once your buddy has recovered check for any injuries and insist they stop diving for the rest of the day.

Question 36

What to do if your buddy experiences a Black Out

Answer 36

1) Get your buddy to the surface and keep his/her airway out of the water 2) If it is difficult to stay above water then release your own weight belt and/or your buddy's 3) Remove all facial equipment and if your buddy is wearing a neck weight remove this too 4) Attempt to revive your buddy by blowing on their eyes, tapping their cheeks gently with your hand and calmly instructing them to breathe. (Do not shout or squeeze them too tightly as this can cause feelings of danger when they begin to revive) 5) If your buddy does not revive after 10 seconds then pinch their nose and give up to 5 rescue breaths 6) If your buddy still does not revive then proceed to get them out of the water while continuing to give them rescue breaths. When they are out of the water seek medical assistance and commence CPR. 7) When your buddy recovers from a black out insist they stop diving for the rest of the day

Question 37

What is Boyle's Law?

Answer 37

At a fixed temperature the volume of a gas is inversely proportional to the pressure exerted by the gas.

Question 38

What is the implication of Boyle's law for freedivers?

Answer 38

When we freedive the surrounding pressure increases. Gases in our body, like in the lungs, sinuses and ears will be most affected by the increase in pressure. Tese gasses will decrease in volume as we descend and the surrounding pressure increases. We need to compensate for the decrease in gas volume in order to avoid damaging tissues in our bodies. We use equalization techniques to do this.

Question 39

Write down a table with Depths of 0, 10m, 20m and 30m and the corresponding pressure in Bar, Lung Volume (Starting at 8L at 0m) and Volume Ration (Starting at 1 at 0m)

Answer 39

Depth: 0 Pressure: 1 Lung Volume: 8L Volume Ratio: 1 Depth: 10m Pressure: 2 Lung Volume: 4L Volume Ratio: 1/2 Depth: 20m Pressure: 3 Lung Volume: 2.66L Volume Ratio: 1/3 Depth: 30m Pressure: 4 Lung Volume: 2L Volume Ratio: 1/4

Question 40

What air spaces need to be equalised?

Answer 40

The airspaces in the ears, the sinuses and mask need to be equalised when freediving

Question 41

What are the three parts of the ear?

Answer 41

The Outer Ear (Fleshy bit outside head and ear canal to the eardrum) The Middle Ear (the air filled cavity behind the ear drum) The Inner Ear contains the actual hearing organs including the cochlea which is filled with fluid and so does not need to be equalised.

Question 42

Describe the role of the Eustachian tube in equalisation

Answer 42

The Eustachian tube connects the middle ear to the nasal section of the throat. It is usually closed, isolating the middle ear from the atmosphere It opens when we swallow or apply positive pressure. When we equalise during a dive we are actively opening the eustachian tube.

Question 43

Describe what happens to the ear as we descend on a dive? How do we correct it?

Answer 43

The air in the middle air compresses and pulls the eardrum towards the middle ear, placing strain on it. We need to push air from the back of the throat though the eustachian tube and into the middle ear to equalise within the first 2-3 meres and regularly thereafter while descending

Question 44

What happens if we fail to equalise?

Answer 44

If the freediver continues to dive barotrauma will occur with potential for hearing loss, infection and vertigo

Question 45

Describe the valsalva maneuver. What is the popping sensation?

Answer 45

The simplest form of equalisation 1) Pinch the nose 2) Close the mouth and keep it sealed 3) Gently exhale until a popping is felt in the ears The popping sensation is the opening of the eustachian tubes in the ears

Question 46

Describe the Frenzel Maneuver and who uses it primarily

Answer 46

The Frenzel maneuver is one of the most efficient forms of equalisation available to free divers 1) The glottis in the throat is closed and the nose is pinched 2) The tip of the tongue is placed behind the top row of teeth, and the sides of the tongue are pressed against the top rows of teeth and the roof of the mouth creating a sealed airspace in the back of the throat 3) The tongue is then pushed backwards towards the throat, the air is compressed enough to open the eustachian tubes and a popping sensation is felt.

Question 47

How are the sinuses equalised? What could prevent the sinuses equalising? What could be done to help?

Answer 47

The sinuses are usually equalised automatically when the ears are equalised. Congestion Flush Sinuses (Neti Pot), avoid dairy, avoid smoke or aircon, stay hydrated, breath steam

Question 48

What is a reverse block? What should you do if you experience one?

Answer 48

This is when the air expands on the acent but is unable to move back into the throat due to blockages Try to ascend as slowly as possible while wiggling jaw or simulating a yawn

Question 49

When we descend what else must we equalise and how?

Answer 49

The mask must be equalised by breathing out a little through the nose when the mask starts to feel tight on the face

Question 50

What is the golden rule of free diving?

Answer 50

Never free dive alone You and your partner should be capable of the depth you are diving and fully trained in rescue techniques.

Question 51

Why shouldn't you scuba dive before free diving?

Answer 51

Wait at least 12 hours after scuba to free dive to avoid decompression sickness.

Question 52

Why should you not eat shortly before free diving?

Answer 52

A full stomach with divert blood to your digestive system and make you feel uncomfortable in the water limiting your ability.

Question 53

Why is staying hydrated important?

Answer 53

Dehydration will increase the likelihood of blackout

Question 54

What must you do with your dive partner/s before you get in the water

Answer 54

Plan your dive with your partner

Question 55

What breathing should you not do before free diving?

Answer 55

Hyperventilation

Question 56

What must be used if there is boat traffic?

Answer 56

Dive flag

Question 57

What is the negative of being overweighted on the descent and ascent?

Answer 57

Descent - equalisation problems Ascent - Unceccessary effort and energy expenditure

Question 58

At what depth should we aim to be neutrally buoyant?

Answer 58

10 to 15m

Question 59

How should a snorkel be used when freediving? Why?

Answer 59

Remove the snorkel from your mouth when diving Keeping it in complicated equalisation and can cause inhalation of water when you have contractions. Blasting the snorkel can always lead to blackout

Question 60

When should ears be equalised?

Answer 60

Before the feeling of pressure or pain

Question 61

Should you exhale under water? Why/Not?

Answer 61

Never as it can lead to blackout and reduces your buoyancy

Question 62

What is a good rule of thumb for the ratio of recovery to dive time?

Answer 62

Rest for double the time you spent underwater. For example 1 min dive, 2 min rest

Question 63

Where should you look while freediving and why?

Answer 63

Keep the chin tucked in close to the chest The extension of the neck creates a poor hydrodynamic position, makes equalisation more difficult, contricts blood flow to the brain and increases the likelihood of respiratory barotrauma.