The World of Recreational Diving

SCUBA is an acronym for the S______ C______ U________ B________ A________ invented by Cousteau.

Diver certification is required to avoid the dangers that proper training can prevent.

There are two types of Certification ________and NAUI

PADI and NAUI•Each agency teaches the same principles, but in different ways.• PADI is geared more toward recreational diving (during initial instruction). •NAUI goes more in depth in technical matters related to diving and specialty.

•NAUI is a not-for-profit agency, founded in 1960• PADI is a for-profit agency, founded in 1966.

• PADI offers shorter courses than NAUI with more levels •PADI and NAUI utilize different dive tables.

• NAUI's dive tables tend to be more conservative

During WWII, _________ invented SCUBA and many other devices that opened the oceans to millions.

Monaco Museum of Oceanography - Jacques Cousteau was the director for 30 years until his death in 1997.

Dive flags are used to let boaters and others in the area know that there is a Diver Down in the Water.

Helps Prevent Divers getting their hair parted by a propeller

• The air we breathe is

• 78% __________

• 20.9 % Oxygen

• 1.1% Misc. Gases

• Air is compressible – meaning that when pressure is applied to a volume of air it can be forced to occupy a smaller area.

• A scuba tank will hold compressed air

A full tank will be 7-8lbs heavier than

an empty one

• Air continues to be affected by pressure as you dive

• As pressure increases Volume decreases This is known as _______ Law

At the surface we are under 14.7 pounds of pressure from the air in our atmosphere

• This is called 1 ___________or 1 ATM

• As we descend in the water every 10 meters or 33 feet the pressure increases by one ATM

• If you dive down 10 meters you have doubled the pressure to 2 ATM’s and have halved the volume of air in your Air Tank.

• Inversely the air will expand as pressure is relived.

• This is why you should never _____________ as you ascend through the water. It may result in serious damage to your lungs

• Vision – Your eyes are designed to focus light rays in air. A mask will create an air pocket between the water and your eyes

• Colors- light is composed of seven different colors remember ROY G BIV?

• Blue penetrates the deepest Red the least

because of this you see different colors at different depths

• Hearing

• Due to the density of water sound waves travel ____________ faster in water.

• Again your ears are designed for detecting sound in air. The sound moves so fast in water it is difficult to tell where a sound is coming from.

Heat Loss – water is denser and has the ability to absorb heat quickly. Heat is conducted out of your body ________faster in water than air!

Water temperature is a big factor for survival that experience, training and safety procedures can not overcome.

at 80o almost indefinite time limit in the water

at 60o 2-24 hour time limit

at 50o 30 minutes to 3 hours limit

at 32o less than one hour limit

There are three types of Buoyancy

1.Negative Buoyancy – ________________

2. Neutral Buoyancy – ____________________

3. Positive Buoyancy- ____________________

Divers Always want a Neutral Buoyancy

1

2

3

1. Decompression sickness _________- caused by surfacing too rapidly for excess nitrogen in your blood to be eliminated by breathing.

The result is bubbles that expand and damage body tissue, cause pain and or Death

Divers learn to surface slowly and when to make necessary decompression stops.

2. _________ _________ - at depths, nitrogen is forced into the blood stream and has an anesthetic quality that impairs judgment and may cause the diver to become unconscious.

The depth that narcosis occurs depends on the experience of the diver and the length of the dive.

Nitrogen and You

• Nitrogen is an ______ ____ meaning it does not do anything while in your system.

• The body always tries to maintain equilibrium• The amount of nitrogen you are breathing in at

depth is more than there is resident in your body.

• Your body will take on excess nitrogen to equal that.

• As pressure is reduced then the excess will release accordingly.

• Too much too fast can cause the bends

• Even if you decompress correctly excess nitrogen will be in resident in your system.

• It will take 24 hours for your body to return to the state it was in prior to your first dive

• Using ______ _______ correctly help you to understand your limits and prevent any problems due to nitrogen

The Importance of Dive Tables

• Dive tables allow you to understand your time limits in water due to nitrogen ingassing

• Dive tables are essential when you are making more than one dive in a day.

Equipment

Equipment

• Buoyancy Compensator Vest – aka BC

The Vest can be inflated or deflated to adjust buoyancy

A last breath of air can be used from Vest

• Regulator- includes mouthpiece and Octopus. Attached to tank and Vest.

Tank – Holds compressed air or Air mix

• Snorkel Mask Fins

• Wetsuits come in various types depending on the conditions you are diving under.

• Their purpose is to conserve body heat.

• 1.5 mm to 7mm in thickness There are also dry suits used in diving

Table 1

Table 2

Table 3

Planning a Dive• Record your planned Dive Depth• Add 3 meters• Write in the Maximum Dive Times (MDT)

for each. – Found on Chart #1• Record the time in the water and the time

out of the water.• From that time subtract 3 minutes for a

compression stop – Adjusted Dive Time (ADT)

• ALWAYS ROUND UP

• The First Dive of the Day you Start out in Group Letter A

• Use Chart #2 to determine your SIT time and new letter Group for your next dive.

• Use Chart #3 for the Adjusted Maximum Dive Time for your depth (The bottom number) again add 3 meters and find the AMDT for that depth as well.

• After your dive add your time in the water plus your Residual Nitrogen Time (RNT) (The top number on Chart #3) To find your total Nitrogen Time.

• Go back to Table #1 to determine your new Dive Letter Group.

DIVE #1

• You are planning a Dive for 18 Meters

• You entered the Water at 10:00am and exited the water at 10:37am with a three minute compression stop

• Your Maximum depth was 17meters

• DRAW OUT YOUR DIVE CHART

DIVE #2

• You plan a Dive of 24 Meters

• You enter the water at 9:00 am and exit the water at 9:25 with a 3 minute compression stop

• Your maximum depth was 25 meters

• DRAW YOUR DIVE CHART

Dive #3

• You plan a 12 meter dive

• You enter the water at 8:45am and exit the water at 9:45am with a 3 minute compression stop.

• Your Maximum depth was 14 meters

• DRAW YOUR DIVE CHART

Dive #4

• You plan a 21 meter dive

• You enter the water at 10:45am and exit the water at 11:15am with a 3 minute decompression stop.

• Your Maximum depth was 16 meters

• DRAW YOUR DIVE CHART

Dive #5• You plan a 18 meter dive• You enter the water at 10:00am and exit

the water at 10:37am with a 3 minute decompression stop.

• Your Maximum depth was 18 meters• What is your dive letter?• What is the MINIMUM time you need to sit

out to get back to letter A

• DRAW YOUR DIVE CHART

Dive #6

• You plan a 12 meter dive• You enter the water at 6:45am and exit the water

at 7:32 am with a 3 minute decompression stop.• Your Maximum depth was 14 meters• What is your dive letter?• How long do you have to SIT (Minimum) to get

back to A?

• DRAW YOUR DIVE CHART

Dive Quiz

• You plan a 21 meter dive• You enter the water at 8:45am and exit the water

at 9:18 am with a 3 minute decompression stop.• Your Maximum depth was 22 meters• What dive letter are you?• If you are planning a second dive at 1:00 pm

what letter would you be at that time?

• DRAW YOUR DIVE CHART