Scuba Diving: History and Evolution

• Scuba diving's origins involve using hollow reeds to stay underwater longer.
• More effective underwater breathing methods were developed from this simple concept.

Scuba Diving Evolution Timeline

• 1300s: A simple cauldron-shaped bell trapped air, enabling divers to swim out and return to replenish air.
• 1690: Edmund Halley improved the diving bell, supplying air from the surface via barrels and tubes.
• 1715: John Lethbridge built the "diving engine," an underwater oak cylinder supplied with compressed air from the surface.
• 1823: Charles Anthony Deane invented the "smoke helmet" for firefighters, which delivered air from the surface.
• 1825: William James invented the first workable, full-time SCUBA with a cylindrical air reservoir at 450 psi.
• 1837: Augustus Siebe innovated a closed diving suit connected to a surface air pump.
• 1843: The Royal Navy established the first diving school.
• 1866: Benoit Rouquayrol and Auguste Denayrouze patented the "Aerophore," a forerunner to modern scuba gear with a compressed air tank and a surface air hose.
• 1876: Henry A. Fleuss developed the first self-contained diving gear using compressed oxygen and a carbon dioxide absorption system.
• 1943: Jacques Cousteau and Emile Gagnan redesigned a car regulator into the aqualung, which remains the basis for modern SCUBA.

What is Scuba Diving?

• SCUBA stands for Self-Contained Underwater Breathing Apparatus.
• In scuba diving, a diver uses a regulator and a compressed air tank to breathe underwater.
• The equipment enables divers to explore underwater for extended periods and at greater depths.

Basic Scuba Diving Equipment

• Dive mask: Creates an air pocket for clearer underwater vision.
• Snorkel: Allows breathing on the surface while face down.
• Regulator: Connects to the tank and delivers air for underwater breathing.
• BCD (Buoyancy Control Device): Controls the diver's position in the water column.
• Octopus: A backup regulator with a longer hose for emergencies.
• Weight Belt: Counteracts buoyancy.
• SPG (Submersible Pressure Gauge): Shows remaining air in the tank.
• Scuba Tank: Contains pressurized air.
• Fins: Provide propulsion.
• Wet Suit: Protects against cold and other elements.
• Dive Computer: Monitors depth, time underwater, and remaining safe time.
• Dive Lights: Provide light in dark underwater environments.
• Dive Knife: Used for cutting ropes and lines.
• Dive Case: Protects gear during travel.

Skills Needed in Scuba Diving

Pre-Dive

• Pre-dive procedures are essential for diver safety.
• The pre-dive safety check is a standardized procedure to ensure all equipment is functioning before entering the water.
• Divers perform safety checks with a dive buddy.

Pre-Dive Safety Check Steps

• Buoyancy Compensator: Check inflator and deflator buttons and pull string.
• Weights: Verify quick-release system, right-hand release orientation, and clear belt/pocket release.
• Release: Check BCD clips and tank band tightness.
• Air Regulator: Ensure proper regulator function, full scuba tanks (3000 psi or 200 bars), comfortable breathing, and alternate air source location.
• Final Okay: Confirm all gear is in place.

Five-Point Descent

• Signal: Give the thumbs-down signal and wait for acknowledgment.
• Orient: Use a surface object or compass for reference.
• Replace: Remove the snorkel and replace it with the regulator mouthpiece.
• Time-check: Set the timing device.
• Deflate: Deflate the BCD, exhale, and equalize ears.

Descending

• A controlled descent uses lungs and BCD for neutral buoyancy.
• Slow, controlled descents prevent ear barotrauma, damage to aquatic life, separation from dive buddy, and stress.

Descent Steps

• Step 1: BCD Use: Use the BCD for buoyancy control, adjusting to achieve neutral buoyancy.
• Step 2: DO NOT deflate All the Air: Establish neutral buoyancy at the surface, floating at mask-level, then sinking slightly with exhalation.
• Step 3: Exhale Fully: Exhale to begin descent, taking about 10 seconds.
• Step 4: Re-Establish Neutral Buoyancy: Inflate BCD slightly when sinking even during inhalation.
• Step 5: Regroup: Re-establish neutral buoyancy after a few feet, equalize ears, and check depth and dive buddy.
• Step 6: Reaching the Destination: Descend by exhaling to the intended depth.

Ascending

Ascending safely:

• Signal buddy and begin ascending together.
• Start ascending with adequate air in the tank.
• Ascend slowly, 30 feet/minute; US Navy Dive Tables allow max ascent of 20 feet/minute.
• Breathe continuously; avoid holding your breath.
• Perform a safety stop at 15 feet for 3-5 minutes to eliminate nitrogen.
• Extend one hand overhead, look up, and rotate 360 degrees.
• Drift to the surface, inflate BCD, and signal to the boat.

Health Benefits of Scuba Diving

• Regular diving maintains fitness and stamina.
• Exercising in water improves cardio-vascular performance.
• Muscle tone and strength are improved through water movement and carrying equipment.

F.I.T.T Principles

• Frequency, Intensity, Time, and Type of exercise are key in workout planning.
• F.I.T.T principles help create workouts that suit individual goals and fitness levels.