STARS Open Water Diver Manual

INDEX

Orientation
Transform into a Fish on Your Holidays
Certificate of Fitness for Diving
Certification Card (C-Card)
 
Dive Equipment
Mask
Snorkel
Fins
Gloves/Boots
Diving suits
Weights
Tank
Regulator
Backup Scuba
BC
Gauge
Other Equipment 1
Other Equipment 2
Other Equipment 3
Equipment Setup
Equipment Maintenance
 
Underwater Environment
Topography and Artificial Structures 1
Topography and Artificial Structures 2
Ocean Conditions 1
Ocean Conditions 2
Poisonous Sea Life 1
Poisonous Sea Life 2
Aggressive Sea Life
 
Underwater Physiology
Light and Color
Sound
Drag/Buoyancy
Heat Absorption
Air Composition
Breathing and Circulation Mechanism
Diver Breathing /Air Consumption
Pressure
Pressure and Gas Volume
Lung Over-expansion Injury
Air Embolism
Gas Poisoning
Hyperventilation
Skip Breathing
Decompression Sickness (DCS)
The Human Body’s Air Spaces
Squeeze and Equalization
Specific Squeeze Types
Reverse Block and Equalization
Specific Body Air Cavities and Reverse Block
 
Plan and Rules
Diving Site Selection
Leader and Member
Buddy System
Equipment
Health Maintenance
Refresher Course
Cancellation and Modification
Emergency Plan
Communication
Air Consumption Ratio
Dive Table
Change of the internal nitrogen quantity
Comparison of the internal nitrogen quantity
Constitution of the Dive Table
No-decompression Dive Limit
Residual Group
Surfacing Time
Nitrogen Disappearance Time
Surface Interval Time
No-decompression Dive Limit for the second diving
Residual Nitrogen Time
Residual Group for the second diving
Decompression Stop
Safety Stop
Time Until Safe To Fly
Other attention
Work Sheet
Making a Dive Plan
Multi-Level Diving
Manners
 
Diving Skills
Donning Snorkel Set
Snorkel Clear
Fin Work
Donning the Weight Belt
Head First
Equipment Setup
Entry
Descent
Regulator Clear
Mask Clear
Regulator Recovery
Buoyancy Control
BC Donning and Removal
Weight Belt Donning and Removal
Equipment Release
Dealing with Emergencies 1
Dealing with Emergencies 2
Dealing with Emergencies 3

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Underwater Physiology

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Decompression Sickness (DCS)



When diving, nitrogen is absorbed into the body. After surfacing, nitrogen is released during respiration (called off-gassing). This is a normal process, but if a large amount of nitrogen is absorbed and then the diver surfaces too quickly, the excess nitrogen forms bubbles in the body. Once these bubbles enter the bloodstream, the disruptions they cause are called decompression sickness (DCS).


A Body Filled With Bubbles



■Symptoms of DCS:

As nitrogen absorption varies in the different areas of the body, there are distinct types of DCS – type I (mild); type II (serious) and type III (with Arterial Gas Embolization, or AGE).

Type I is marked by dermopathy such as skin rashes, itchiness, and the like, as well as joint pain (aka “The Bends”). Upper body joint pain is more prevalent, ranging from a dull ache to sharp needle-like pain. Type I DCS accounts for roughly 90% of cases. Less common is type II DCS, with pulmonary symptoms, hypovolemic shock, or nervous system involvement. Type II can leave residual complications, and may lead to death in the worst case scenario.

Undiagnosed, DCS can lead to things such as chronic joint pain and osteonecrosis.


The Bends

Nitrogen Bubble

Blood Vessel



■Decompression Sickness Emergency Care and Prevention

For emergency care, oxygen therapy (100% at 10-15L/min) and immediate transport to a hospital with recompression chamber is key. Prevention includes allowing your body to off-gas as much absorbed nitrogen as possible by slowly ascending from all dives, especially for deep and long dives. Use of dive computers is beneficial as they are programmed to give water depth, dive time, and other data which help you to prevent DCS.

Further, they warn against rates of ascent that are too fast.



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