Presentation is loading. Please wait.

Presentation is loading. Please wait.

BSAC Ocean Diver Training

Similar presentations

Presentation on theme: "BSAC Ocean Diver Training"— Presentation transcript:

1 BSAC Ocean Diver Training
The Body and Effects of Diving

2 The Body & Effects of Diving
Aims The Body Mechanisms Metabolism Respiration Circulation How diving affects them

3 The Body Mechanisms = Metabolism - The process of life Body cells
Energy Food + Oxygen = Body cells Food + Oxygen = Energy Body Cells Waste products removal Water + Carbon Dioxide Two interconnected systems Respiratory system Circulatory system

4 Respiration - The Lungs
The Mechanics of Breathing Vital Capacity 4.5 litre Lung Capacity Tidal Volume litre Residual Volume litre Inhale 21% Oxygen 79% Nitrogen Exhale 17% Oxygen 4% Carbon Dioxide 79% Nitrogen

5 The Lungs - Gas Exchange
The Gas Exchange The Alveoli Oxygen =O2 O2 Carbon Dioxide =CO2 CO2 Air In/Out Blood To Body via Heart Blood From Body via Heart

6 Circulation - Heart and Blood
Circulation - Heart & Blood Lungs OXYGEN Collected in lungs Travels to heart Travels from heart Delivered to body cells CARBON DIOXIDE Collected from body cells Travels to the heart Cells Travels to lungs STIMULUS TO BREATHE The need to expel carbon dioxide

7 Breath Hold Diving and Hyperventilation
Normal Dive O2 CO2 Start Dive O2 Level to support Consciousness CO2 Level for Stimulus to breathe During Dive End Dive Dive with Hyperventilation O2 CO2 Start Dive O2 Level to support Consciousness CO2 Level for Stimulus to breathe During Dive Diver Unconscious

8 Air Spaces affected by Diving

9 The Ear Effects of Diving Ear Drum Middle Ear Eustachian Tube
Inner Ear Outer Ear Ear Drum Eustachian Tube Effects of Diving Sound travels faster underwater - direction difficult to identify Air space - Ear Drum, Middle Ear, Eustachian Tube

10 Effects of Diving on The Ear
Normal on descent Increased pressure and blockage on descent Reverse Ear Never ‘force’ equalisation Ascend to shallow depth (pressure) DO NOT DIVE WITH A COLD

11 The Sinuses - Effects of Diving
Before Dive Mucus membrane Air Block Membrane swelling Membrane rupture Air Blood During Dive Not serious but results in Blood in the mask Sinus pain Do not dive with a cold Bleeding into nasal passage Air Teeth Dental checkups

12 Body Temperature Control
Body heat generated by metabolism Core body temperature maintained at 37oC Cooler surroundings = heat loss Most through head and face Chest front and under armpits Peripheral blood supply restricted Hands, feet, nose, ears Less blood flow = less heat loss Shivering Hypothermia 37oC

13 Heat Loss and Diving Heat Loss In Water 25x faster than air
400 C Normal body temperature 370 C 300 C No suit required Cold water increases rate of heat loss Insulation consideration for divers Wetsuit / Drysuit required 200 C Drysuit required 100 C End the dive if getting cold 00 C

14 Insulation Wet & Semi Dry Suits
Comfortable close fit One or two piece Hood and gloves Boots if strap fins Body Water Wet Suit Maintenance Wash in fresh water

15 Insulation - Dry Suits Maintenance - Wash in fresh water
Neoprene Dry Suit Membrane Dry Suit Body Water Under Suit Air Body Air Water Comfortable fit Strap fins Hood & gloves Maintenance - Wash in fresh water

16 Buoyancy = = + Object submerged Density
Archimedes principle When an object floats in water it displaces a weight of water equal to its own weight Object submerged Water displaced = Force (Upthrust) = water displaced Density Object sinks Weighs more than upthrust (Heavier than water displaced) = + Air Object floats Weighs less than upthrust (Lighter than water displaced)

17 Buoyancy and Divers Positive Buoyancy Neutral Buoyancy
Too light Physically tiring Uncontrolled upward movement Neutral Buoyancy Positive Weightless state Reduces physical effort Negative Buoyancy Neutral Too heavy Self or marine life damage Risk of going too deep Negative

18 Buoyancy & Diving Descent During dive Ascent
Combined effect of diver’s body, suit and SCUBA - positive buoyancy May need additional weight During dive Fine tuning with lungs Ascent Air will expand Controlled dumping of air equalises diver’s buoyancy Buoyancy check - correct weighting

19 Exhaustion & Diving An inability to meet physical demands
Buoyancy problems Getting cold underwater Working hard underwater Mental tiredness or anxiety Lack of general fitness The night before! Always ask the question : Are you fit to go diving?

20 Summary The Body Mechanisms How diving affects them
Metabolism Respiration Circulation How diving affects them Ensure fitness to dive


Download ppt "BSAC Ocean Diver Training"

Similar presentations

Ads by Google