PADI open water diver video

Recently I watched an official PADI (free) DVD on becoming an Open Water Diver. It discussed the basic principles of beginner diving, which were educational, 11 sections on special types of diving that were also informative to find an area of interest, and a video highlighting two people’s experiences with diving. I felt it gave a good educational base of what an Open Water Diver will need to know, it demonstrated the practice of beginner principles, and generated excitement over scuba diving. Here are the main things I learned:

Buoyancy- water buoys up an object with a force equal to the weight of the water the object displaces.
Positively buoyant- If an object weighs less than the water it displaces, it floats.
Negatively buoyant- An object weighs more than the water it displaces, it sinks
Neutrally buoyant- An object neither floats nor sinks.
You control your buoyancy with your BCD (Buoyancy Control Device).

Air pressure is the air’s weight caused by gravity holding the atmosphere against the earth.

Depth, Pressure, Air volume, Air density, Surface vol. equiv.
0m/ 0ft, 1 bar /ata, 1, x1, x1
10m/ 33ft, 2 bar / ata, 1/2, x2, x2
20m/ 66ft, 3 bar / ata, 1/3, x3, x3
30m/ 99ft, 4 bar / ata, 1/4, x4, x4

Equalize pressure frequently as you descend.
Breathe continuously and NEVER hold your breath while ascending or descending.
When air compresses under pressure, it becomes denser.
Scuba gear supplies air to you at the surrounding pressure, so at 20m you use your air 3 times faster than at the surface. The deeper you dive, the faster you use your air.

Equipment:
MASK- find one that fits well (place the mask on your face, inhale and exhale through your nose and it should suction to your face comfortably). When you get it home, gently scour the inside of your mask with a low abrasion cleaner or toothpaste. If you don’t, you won’t be able to defog it for diving.
SNORKEL- it allows you to rest at the surface without using tank air. It should be attached on the left side of your mask.
FINS- full foot fins are convenient and suitable for warm water diving where you don’t need additional foot protection. Most divers opt for open heeled fins with wet suit boots that provide insulation and protection. Rinse inside and outside of all gear with fresh water after all uses.

Buoyancy Control Device:
Most BCDs are jacket style that include a large inflation/ deflation hose, a low-pressure inflator mechanism, and an over pressure leak valve. Most divers prefer a weight integrated BCD so it eliminates the need for a separate weight belt.

Scuba tank and valves:
Yoke valves- most common. Regular attaches to a Yoke assembly.
DIN valves- Regulator screws into the valve. It handles somewhat higher pressures.
Valves should open and close smoothly. They all require an “o-ring” to seal water out. Never drain the cylinder completely; always leave a few bar / a couple hundred PSI to keep moisture and contaminates from entering.

Regulator:
SPG- Submersible Pressure Gauge. This tells you how much air you have during a dive.

Confined water- dive 1:
Assembling scuba equipment
Adjustments and gearing up
Breathing underwater
Regulator clearing
Regulator recovery
Mask clearing
Swimming underwater
Equalization and underwater swimming
Managing your air
Alternate air source
Extra second stage
Alternate inflator regulator
Ascending
Exiting the water
Equipment disassembly and care