SCUBA

By Martin Stein

Objectives

• At the end of the lesson the student will always understand the dangers involved in Scuba diving.

• The student will be able to match the seven required pieces of Scuba equipment with their function.

Subjects

1. Diving Physiology

2. Diving Physics

3. AGE & DCS

4. Equipment

5. Buoyancy

6. The Diving

Your Body• The heart pumps your

blood, to the lungs, back to the heart, out to the body, back to your heart.

• Gases are exchanged in the lungs and in the body (muscles and organs).

The Gases

• Air is made up of 21 % oxygen, 78% nitrogen and 1% other gases.

• Throughout our everyday lives we are saturated with 78% nitrogen and between 18%-21% oxygen. Our bodies we are used to this.

Gas Laws

• Charles law- temperature and volume• Boyles law- pressure volume relationship• Dalton's law- partial pressures• Hennery's law- absorption

Taking on Gases

• As you descend in the water the pressure on your body increases. Your body compensates for this by taking on more gases.

• Your body takes on dissolved gases

Everything must be Equal

• As we spend time at depth are bodies are racing to equalize the pressure differences.

• The longer you stay down the more gases your body takes on.

Off Gassing

• When the dive is over and we ascend the gas exchange reverses direction. It’s time to off gas.

• This is where it can all go wrong.• If you follow all the rules /tables for diving

everything should be fine.• Decompression Sickness

AGE

• Arterial Gas Embolism- Gases force into the arterial system, usually in the lung.

• Effects are immediate symptoms appear within 10 minutes.

AGE Symptoms

• Disorientation• Chest pain• Paralysis • Weakness• Dizziness• Blurred vision• Personality change

• Convulsions• Other neurological • Unconsciousness• Stopped breathing• Marbling of the skin• Death

Academies Principal

• It states that "any object wholly or partially submerged in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the body."

Equipment

• 7 pieces

1. Fins

2. Weights

3. Tank

4. Regulator

5. Gauges (Depth/Psi)

6. BC

7. Mask

Assemble and Inspect Your Gear

• As you put your tank in your BC inspect it.• Inspect your regulator and hoses.• Inspect your mask, fins, and weight belt.• Test everything on the surface before

putting it on.

• Get dressed.

Gear Up Get In

During the Dive

• Check your air pressure frequently• Watch your depth when moving up and

down on the reef.• Watch your time

Surfacing

• Signal your buddy• Check your air • Remove some air from your BC.• Ascend slowly to the surface at no more

than 30 Feet Per Minute.• As you reach the surface raise your hand

over your head. Signal the boat w/OK

Exiting the Water

• When you reach the ladder remove fins, ensure no divers are behind you and climb the ladder. People on the boat with assist you removing your gear.

Summary

• Body Physiology• Effects of Gases• Diving Illnesses• Equipment• Buoyancy• Diving

Questions ?