A BRIEF HISTORY OF DIVING, FROM ANTIQUITY TO THE PRESENT
Men and women have practiced breath-hold diving for centuries. In ancient Greece breath-hold divers are
known to have hunted for sponges and engaged in military exploits. Of the latter, the story of Scylla’s serves as a
proof of this statement. During a naval campaign the Greek Scyllis was taken aboard ship as prisoner by the Persian
King Xerxes I. When Scyllis learned that Xerxes was to attack a Greek flotilla, he seized a knife and jumped
overboard. The Persians could not find him in the water and presumed he had drowned. Scyllis surfaced at night
and made his way among all the ships in Xerxes's fleet, cutting each ship loose from its moorings; he used a hollow
reed as snorkel to remain unobserved. Then he swam nine miles (15 kilometers) to rejoin the Greeks with victory.
The desire to go under water has probably always existed: to hunt for food, uncover artifacts, repair ships
(or sink them!), and perhaps just to observe marine life.
In the 16th century people began to use diving bells supplied with air from the surface, probably the first
effective means of staying under water for any length of time. The bell was held stationary a few feet from the
surface, its bottom open to water and its top portion containing air compressed by the water pressure. A diver
standing upright would have his head in the air. He could leave the bell for a minute or two to collect sponges or
explore the bottom, then return for a short while until air in the bell was no longer breathable.
In England and France, full diving suits made of leather were used to depths of 60 feet. Air was pumped
down from the surface with the aid of manual pumps. Soon helmets were made of metal to withstand even greater
water pressure and divers went deeper. By the 1830s the surface-supplied air helmet was perfected well enough to
allow extensive salvage work.
By the 1830s the surface-supplied air helmet was perfected well enough to allow extensive salvage work.
Starting in the 19th century, two main avenues of investigation - one scientific, the other technologic greatly accelerated underwater exploration. Improvements in technology - compressed air pumps, carbon dioxide
scrubbers, regulators, etc., - made it possible for people to stay under water for long periods.
There are really four 'mini-histories' in the fascinating story of man's desire to explore beneath the sea; they
correspond to four separate methods of diving, of which scuba is but the latest.
WHAT DOES 'SCUBA' STAND FOR?
SCUBA is an abbreviation for Self-Contained Underwater Breathing Apparatus, in other words, equipment
to allow us to breathe underwater. "Diving with scuba" signifies using apparatus that is completely carried by the
diver and not connected to the surface, hence self-contained.
The air that is in the tanks is compressed air as we know it outside, so parts nitrogen, parts oxygen, and
some other gases as well. Because of the nitrogen in the compressed air, divers need to be very careful when diving
to greater depths, as nitrogen narcosis can occur, which has the same effect as excessive alcohol.
HOW POPULAR IS SCUBA DIVING?
An estimated 2.5-3.5 million Americans participate in recreational scuba diving. Another 500 thousand
become certified each year in the United States. In the early days of scuba diving (roughly 1950-1970), participants
were predominately young men. Today the sport is enjoyed by people in all age groups and both sexes. And why
not? Just about any teenager or adult who enjoys the water and can swim, and who does not have heart or lung
impairment, can learn to scuba dive. It does not take great physical strength or unusual exercise tolerance. All it
takes is the desire, plus some basic classroom and in-water training.
Scuba originally began with military and commercial applications, where it is still employed. However, by
far its widest use, in terms of number of participants, is recreational. Recreational scuba today is like other any other
sport that requires specialized equipment and training, such as snow skiing, sailing, mountain climbing and
horseback riding. This section will provide an overview of recreational scuba diving, and explain how it differs
from other forms of diving with scuba equipment.
WHAT ARE THE EQUIPMENTS IN SCUBA?
Finding the right diving equipment and scuba diving gear is essential to having a good and safe diving
experience. Whether you’re a beginner scuba diver or an experienced diver, everyone needs to have the same high
quality equipment and the knowledge about how to use it properly.
1.0
EQUIPMENTS FOR NAVY USE
Open-Circuit Scuba.
All open-circuit scuba authorized for Navy use employ ademand system that supplies air each time
the diver inhales. The basic open-circuitscuba components are: Demand regulator assembly, One or more
air cylinders, Cylinder valve and manifold assembly, Backpack or harness
1.1
The Demand Regulator Assembly
It is the central component of
the
open-circuit
system.
The
regulator delivers air to the diver
after reducing the high-pressure air
in the cylinder to a pressure that can
be used by the diver.
1.2
Cylinders.
Scuba cylinders (tanks or bottles) are designed to hold
high pressure compressed air. Because of the extreme stresses
imposed on a cylinder at these pressures, all cylinders used in
scuba diving must be inspected and tested periodically.
Approved scuba cylinders are available in several sizes and one
or two cylinders may be worn to provide the required quantity of
air for the dive. The volume of a cylinder, expressed in actual
cubic feet or cubic inches, is a measurement of the internal
volume of the cylinder. The capacity of a cylinder, expressed in
standard cubic feet or liters, is the amount of gas (measured at surface conditions) that the cylinder holds
when charged to its rated pressure.
1.3
Cylinder Valves and Manifold Assemblies.
Cylinder valves and manifolds makeup the
system that passes the high-pressure air from the
cylinders to the first-stage regulator. The cylinder valve
serves as an on/off valve and is sealed to the tank by a
straight-threaded male connection containing a neoprene
O-ring on the valve’s body
1.4
Backpack or Harness.
A variety of backpacks or
harnesses, used for holding the scuba
on the diver’s back, have been
approved
for
Navy
use.
The
backpack may include a lightweight
frame with the cylinder(s) held in
place with clamps or straps. The usual system for securing the cylinder to the diver uses shoulder and waist
straps. All straps must have a quick-release feature, easily operated by either hand, so that the diver can
remove the cylinder and leave it behind in an emergency.
2.0
MINIMUM EQUIPMENTS
2.1
Face Mask or Diving Mask
Human eyes were not designed to work
well
under
water—particularly
saltwater.
Therefore, one of the most important things you
will need is a diving mask. The face mask
protects the diver’s eyes and nose from the
water. Additionally, it provides maximum visibility by putting a layer of air between the diver’s eyes and
the water. Face masks are available in a variety of shapes and sizes for diver comfort. To check for proper
fit, hold the mask in place with one hand and inhale gently through the nose. The suction produced should
hold the mask in place.
Don the mask with the head strap properly adjusted, and inhale gently through the nose. If the mask
seals, it should provide a good seal in the water. Some masks are equipped with a one-way purge valve to
aid in clearing the mask of water. Some masks have indentations at the nose or a neoprene nose pad to
allow the diver to block the nostrils to equalize the pressure in the ears and sinuses. Several models are
available for divers who wear eyeglasses.
2.2
Life Preserver or SCUBA Diving Vest
The principal functions of the life preserver are
to assist a diver in rising to the surface in an emergency
and to keep the diver on the surface in face-up position
(Figure below). The low-pressure inflation device on the
preserver maybe actuated by the diver, or by a dive
partner should the diver be unconscious or otherwise
incapacitated.
In selecting a life preserver for a specific task,
the individual technical manuals should be consulted. The use of
certain closed and semi-closed UBAs will require the wearing of a life
preserver. The life preserver must be sturdy enough to resist normal
wear and tear, and of sufficient volume to raise an unconscious diver
safely from maximum dive depth to the surface. Most life preservers
currently in use employ carbon dioxide (CO2) cartridges to provide
inflation in an emergency.
2.3
Buoyancy Compensator
When a life preserver is not required by a specific
UBA, a buoyancy compensator may be used at the Diving
Supervisor’s discretion. When selecting a buoyancy
compensator, a number of factors must be considered.
These factors include: type of wet suit, diving depth,
breathing equipment characteristics, nature of diving
activity, accessory equipment, and weight belt.
As a buoyancy compensating device, the compensator can be inflated by a low-pressure inflator
connected to the first-stage regulator, or an oral inflation tube. The compensator is used in conjunction with the
diver weights to control buoyancy in the water column by allowing the diver to increase displacement through
inflation of the device, or to decrease displacement by venting.
2.4
Weight Belt.
Scuba is designed to
have
nearly
neutral
buoyancy. With full tanks, a
unit tends to have negative
buoyancy, becoming slightly positive as the air supply is consumed. Most divers are positively buoyant and
need to add extra weight to achieve a neutral or slightly negative status. This extra weight is furnished by a
weighted belt worn outside of all other equipment and strapped so that it can easily released in the event of
an emergency. Each diver may select the style and size of belt and weights that best suit the diver. A number
of different models are available.
A weight belt shall meet certain basic standards: the buckle must have a quick-release feature,
easily operated by either hand; the weights (normally made of lead) should have smooth edges so as not to
chafe the diver’s skin or damage any protective clothing, and the belt should be made of rot- and mildewresistant fabric, such as nylon webbing.
2.5
Knife
Several types of knives are available. Diving
knives should have corrosion-resistant blades and a
handle of plastic, hard rubber, or wood. Handles made
of wood should be waterproofed with paint, wax, or
linseed oil. Handles of cork or bone should be
avoided, as these materials deteriorate rapidly when
subjected to constant saltwater immersion. Cork may
also float the knife away from the diver.
Knives may have single- or double-edged blades with chisel or pointed tips. The most useful knife has
one sharp edge and one saw-toothed edge. All knives must be kept sharp. The knife must be carried in a suitable
scabbard and worn on the diver’s life preserver, hip, thigh, or calf. The knife must be readily accessible in terms
of danger, must not interfere with body movement, and must be positioned so that it will not become fouled
while swimming or working. The scabbard should hold the knife with a positive but easily released lock.
2.6
Swim Fins.
Swim fins increase the efficiency of the diver,
permitting faster swimming over longer ranges with less
expenditure of energy. Swim fins are made of a variety
of materials and styles. Each feature—flexibility, blade
size, and configuration—contributes to the relative power
of the fin. A large blade will transmit more power from
the legs to the water, provided the legs are strong enough to use a larger blade. Small or soft blades should
be avoided. Ultimately, selection of blade type is a matter of personal preference based on the diver’s
strength and experience.
2.7
Wrist Watch.
Analog diver’s watches must be waterproof, pressure
proof and, equipped with a rotating bezel outside the dial that
can be set to indicate thee lapsed time of a dive. A luminous
dial with large numerals is also necessary. Additional features
such as automatic winding, nonmagnetic components, and
stop watch action are available. Digital watches, with a stop
watch feature to indicate the elapsed time of a dive, are also
approved for Navy use.
2.8
Depth Gauge
The depth gauge measures the pressure
created by the water column above the diver and is
calibrated to provide a direct reading of depth in
feet of sea water. It must be designed to be read
under conditions of limited visibility. The gauge
mechanism is delicate and should be handled with
care. Accurate depth determination is important to
a diver’s safety. The accuracy of a gauge must be
checked in accordance with the planned maintenance system or whenever a malfunction is suspected. This
can be done by taking the gauge to a known dept hand checking the reading, or by placing it in a
recompression chamber or test pressure chamber for depth comparison.
3.0
OPTIONAL EQUIPMENTS
Protective Clothing.
A diver needs some form of protection from cold water, from heat loss during long exposure in
water of moderate temperature, from chemical or bacterial pollution in the water, and from the hazards
posed by marine life and underwater obstacles. Protection can be provided by wet suit, or a dry suit with or
without thermal underwear
3.1
Wet Suits
The wet suit is a form-fitting suit, usually made of closed-cell neoprene. The
suit traps a thin layer of water next to the diver’s skin, where it is warmed by the
diver’s body. Wet suits are available in thicknesses of 1/8-, 3/16-,3/8-, and 1/2-inch,
with the thickest providing better insulation. The selection of the type of wet suit used
is left to each diver Proper fit is critical in the selection of a wet suit. The suit must
not restrict the diver’s movements. A custom-fitted suit is recommended. The
performance of a suit depends upon suit thickness, water temperature, and water
depth.
3.2
Dry Suits
The Variable Volume Dry Suit (VVDS) has proven to be effective in
keeping divers warm in near-freezing water. It is typically constructed of 1/4inchclosed-cell neoprene with nylon backing on both sides. Boots are provided as
an integral part of the suit, but the hood and three finger gloves are usually
separate. The suit is entered by means of a water- and pressure-proof zipper.
Inflation is controlled using inlet and outlet valves which are fitted into the suit.
3.3
Gloves
Gloves are an essential item of protective clothing. They can be made
of leather, cloth, or rubber, depending upon the degree and type of protection
required. Gloves shields the hands from cuts and chafing, and provide
protection from cold water. Some styles are designed to have insulating
properties but may limit the diver’s dexterity.
3.4
Compass
Small magnetic compasses are commonly used in
underwater navigation. Such compasses are not highly accurate,
but can be valuable when visibility is poor. Submersible wrist
compasses, watches, and depth gauges.
3.5
Writing Slate
A rough-surfaced sheet of acrylic makes an
excellent writing slate for recording data, carrying or
passing instructions, and communicating between divers.
A grease pencil or graphite pencil should be attached to the
slate with a lanyard.
3.6
Signal Flare
A signal flare is used to attract
attention if the diver has surfaced away from
the support crew. Any waterproof flare that
can be carried and safely ignited by a diver can
be used. These are day-or-night signals that
give off a heavy red dish or orange smoke for
daytime and a brilliant red light at night. Each signal lasts for approximately 20 seconds. For safety, each
diver should carry a maximum of two flares.
3.7
Acoustic Beacons
Acoustic beacons or pinger are battery-operated devices that emit highfrequency signals when activated. The devices may be worn by divers to aid in
keeping track of their position or attached to objects to serve as fixed points of
reference. The signals can be picked up by hand-held sonar receivers, which are
used in the passive or listening mode, at ranges of up to 1,000 yards. The handheld sonar enables the search diver to determine the direction of the signal source
and swim toward the pinger using the heading noted on a compass.
3.8
Lines and Floats
A lifeline should be used when it is
necessary to exchange signals, keep track of
the diver’s location, or operate in limited
visibility. There are three basic types of
lifelines: the tending line, the float line, and
the buddy line. Any line used in scuba
operations should be strong and have neutral
or slightly positive buoyancy. Nylon, Dacron, and manila are all suitable materials. Always attach a lifeline
to the diver, never to a piece of equipment that may be ripped away or may be removed in an emergency.
3.9
Snorkel.
A snorkel is a simple breathing tube that allows a diver to swim
on the surface for long or short distances face-down in the water. This
permits the diver to search shallow depths from the surface, conserving
the scuba air supply. When snorkels are used for skin diving, they are
often attached to the face mask with a lanyard or rubber connector to the
opposite side of the regulator.
3.10
Submersible Cylinder Pressure Gauge.
The submersible cylinder pressure gauge provides the diver
with a continual read-out of the air remaining in the cylinder(s) When
worn, the gauge and hose should be tucked under a shoulder strap or
otherwise secured to avoid its entanglement with bottom debris or
other equipment. The gauge must be calibrated in accordance with the
equipment planned maintenance system.
WHAT ARE THE GAS LAWS AND WHY ARE THEY IMPORTANT TO DIVING?
Scuba diving is all about getting gas into your body while you are under water. What complicates scuba
diving is the way gasses behaves at depth, under pressure, in your body and in your equipment. To dive safely and
effectively, you need to understand all the behavior of gasses intuitively and how they affect the techniques and
practice of scuba diving. I will introduce the gas laws in this section and, in Chapter 5, use them to further explain
physiology under water. The four important gas laws are those of the Englishmen Robert Boyle (1627-1691), John
Dalton (1766-1844), and William Henry (1774-1790), and the Frenchman Jacques Charles (1746-1823).
1.0
SCUBA GAS LAWS- BOYLE’S LAW
Boyle's law states:
At constant temperature, the volume of a gas varies inversely with the pressure, while the density of a gas
varies directly with pressure.
Mathematically,
𝑃1 𝑉1 = 𝑃2 𝑉2
where P and V are the pressure and volume, respectively. Change P, and V will change in the opposite
direction, so that their product is maintained at a constant value.
A. Suppose that SCUBA divers often wear a wet suit to help keep them warm while diving. A wet suit is
made of foam rubber or similar material that traps small air bubbles. The air bubbles provide insulation,
but also cause divers to float. To overcome the tendency to float, divers carry weights. But as divers
descend, their wet suit becomes less buoy-ant. When this happens, the problem is how to deal with the
weights they brought from the surface. Most divers blow air from their tank into an inflatable vest called
a buoyancy compensator (“BC” for short) to balance the extra weight. When a diver returns to the
surface, she has to release air from her BC to keep from rising too quickly. How does Boyle’s law explain
what hap-pens to the wet suit and BC? The pressure on a diver’s body increases by one atmosphere for
every ten meters of depth. So at the surface, a diver is under a pressure of one atmosphere (about 14 lb
per square inch). Ten m down, the diver is under a pressure of two atmospheres; 20 m down, the pressure
is three atmospheres, and so on.
Discussion points:
Boyle’s Law states that the product of the volume and pressure of a gas held at a constant
temperature is equal to a constant (PV = k). So, if the pressure of the gas doubles, the volume will be decreased by
half; and if the volume of a gas doubles, the pressure must decrease by half.
As a diver descends, the pressure increases, so the volume of the air bubbles in her wet-suit decreases. This
makes the wetsuit less buoyant, so she has to put some air into her BC to compensate. When she ascends, the
pressure decreases and her wetsuit becomes more buoyant. In addition, the volume of the air she put into her BC
also increases, making her BC more buoyant. So she has to release air from her BC, or else she would pop to the
surface like a cork!
Boyle’s Law is also important to divers because it means that if a diver takes a lungful of air while he is
underwater, that air will expand in his lungs as he rises to the surface. If he holds his breath, or ascends too rapidly
(like a cork) the expanding air can rupture his lungs. So the golden rules of diving are: Never hold your breath, and
don’t ascend more rapidly than your smallest bubbles
B. Suppose you have a container open on one end that is inverted over water; as the container is
lowered in the water the trapped air will be compressed by the water pressure (Figure 7). Assume
the container holds one liter of air at sea level pressure (one atmosphere). PV = 1 liter x 1 atm. = 1.
Increase the air pressure to 2 atmospheres and Boyle's law predicts the volume of air in the container
will be 1/2 liter.
𝑃1 𝑉1 = 𝑃2 𝑉2
1(1) = 2𝑉2
1
2
2.0
= 𝑉2
SCUBA GAS LAWS- CHARLES’S LAW
Charles's law states:
At a constant pressure, the volume of gas varies directly with absolute temperature. Given a
constant pressure of gas, the higher the temperature the higher the gas volume, and vice versa.
Mathematically,
𝑉1
𝑇1
𝑉
= 𝑇2
2
where V1 and V1 are the beginning and final volume, and T1 and T2 are the beginning and final
temperatures (remember, pressure is kept constant).
A. As SCUBA divers descend, they often encounter layers of water that are significantly
colder than water at the surface. Suppose a diver blows air into his BC at the surface until
he is neutrally buoyant (which means he neither rises nor sinks in the water). As he swims
deeper, he enters a layer of much colder water, and soon finds that he is sinking rapidly
through the water. How does Charles’ Law explain what happened?
Discussion points:
Charles’ Law states that the volume of a given amount of gas is directly proportional to the Kelvin
temperature, provided the amount of gas and the pressure remain fixed.
As the diver enters colder water, the temperature of the air in his BC is reduced. Charles’ Law
predicts that the volume of air will also be reduced in proportion to the change in temperature. Since
buoyancy depends upon the volume of air in the BC, buoyancy will also be decreased, causing the diver to
sink.
3.0
SCUBA GAS LAWS- GAY – LUSSAC’S LAW
Gay – Lussac's law states:
At a constant volume, the pressure of gas is directly proportional with the temperature.
Given a constant volume of gas, the higher the temperature the higher the gas pressure, and vice versa.
Mathematically,
𝑃1
𝑇1
=
𝑃2
𝑇2
where P1 and P1 are the beginning and final pressures, and T1 and T2 are the beginning and final
temperatures.
A. A careless diver leaves a full SCUBA tank in the trunk of a car during a hot summer day.
After several hours, a deafening whistle comes from the trunk and the diver finds that her
tank is empty. She says, “Man, I should have expected this to happen because of GayLussac’s Law!” What did she mean?
Discussion points:
Gay-Lussac’s Law states that for a fixed amount of gas (fixed number of moles) at a fixed volume,
the pressure of the gas is pro-portional to the temperature.
When a filled SCUBA tank is heated, the amount of gas stays the same, and so does the volume of
the tank, but the pressure inside the tank increases as the temperature rises. Eventually, the pressure can
reach the point at which the safety disk inside the tank valve ruptures, allowing the air inside the tank to
escape; and making a very loud noise as it does so!
4.0
SCUBA GAS LAWS- HENRY’S LAW
Henry's law states:
The amount of any gas that will dissolve in a liquid at a given temperature is a function of the
partial pressure of the gas in contact with the liquid and the solubility coefficient of the gas in that particular
liquid.
As the pressure of any gas increases, more of that gas will dissolve into any solution with which it
is in free contact.
Mathematically,
𝑉𝐺
𝑉𝐿
= 𝑎𝑃𝑔
where VG is the volume of a particular gas, VL is the volume of a particular liquid, a is the solubility
coefficient for the gas in that liquid, and Pg is the pressure of the gas in contact with the liquid.
A. At a depth of 20 m, a SCUBA diver’s body is exposed to a pressure of three atmospheres.
If the diver is breathing ordinary air, she is breathing a mixture of several gases; mostly
nitrogen (%), and oxygen (%). Suppose the diver remains at this depth for one hour, and
then returns to the surface. What does Henry’s Law predict will happen to gases dissolved
in the diver’s blood?
Discussion Points:
Henry’s Law states that the mass of a gas which dissolves in a volume of liquid is proportional to
the pressure of the gas. So, as the pressure goes up, more gas will dissolve; and as the pressure decreases,
some of the dissolved gas will “undissolved.” Imagine taking the top off of a bottle of soda to visualize
what “undissolved” looks like (the dissolved substance forms bubbles as it changes back into a gas state).
Henry’s Law predicts that gases dissolved in the diver’s blood under three atmospheres of pressure
will “undissolved” when the pressure is reduced to one atmosphere (at the surface). In fact, if the diver
ascends too rapidly, bubbles will form in her blood and may cause decom-pression sickness (also known
as “the bends”). This is why divers must ascend slowly, and sometimes must pause for a while at shallower
depths, to allow time for the dissolved gases to leave their blood without forming bubbles (like very slowly
removing the cap from a bottle of soda).
5.0
SCUBA GAS LAWS- DALTON’S LAW
Dalton's law states:
The total pressure exerted by a mixture of gases is equal to the sum of the pressures that would be
exerted by each of the gases if it alone were present and occupied the total volume.
The pressure of any gas mixture (e.g., air) is equal to the sum of pressures exerted by the individual
gases (e.g., oxygen, nitrogen, and each of the minor gases).
Mathematically,
𝑃𝑇𝑂𝑇𝐴𝐿 = 𝑃1 + 𝑃2 … 𝑃𝑂𝑇𝐻𝐸𝑅
where PTOTAL is the total pressure of a gas mixture (e.g., air), and P1 and P2 are the partial
pressures of component gases (e.g., oxygen and nitrogen). The term POTHER is used to signify partial
pressures of all other gases in the mixture.
A. Ordinary air contains about 78% nitrogen, 21% oxygen, and small amounts of several other
gases. As a diver descends, the pressure of the air he is breathing increases by about one
atm for every 10 m of depth. Oxygen may become toxic and cause convulsions if it is
breathed at a pressure above 1.4 atmospheres. According to Dalton’s Law, at what depth
should a SCUBA diver be concerned about oxy-gen toxicity if he is breathing ordinary air?
Discussion Points:
Dalton’s Law states that the pressure exerted by a mixture of gases is equal to the sum of the
pressures that would be exerted by the gases individually.
Since air contains about 21% oxygen, so the pressure of oxygen at the surface is about 0.21
atmosphere. Since pressure increases by one atmosphere for every 10 m of depth, the relationship between
depth and pressure is
(pressure) = 1 atm + (depth in m) ÷ (10 m/atm)
So the pressure of air at 10 m would be
1 atm + (10 m) ÷ (10 m/atm) = 2 atm
and the pressure of oxygen at 10 m would be
(21% O2) • (2 atm) = 0.42 atm O2
So, the depth at which oxygen would have a pressure of 1.4 atm is
(depth in m) = [ (1.4 atm) ÷ (21% O2) - 1 atm] • [10 m/atm] = [6.66 atm - 1 atm] • [10
m/atm]= 56.6 m
If your students aren’t up to the algebra, just focus on the idea that the pressure of a mixture of
gases is divided among each of the gases in the mixture, in proportion to the concentration of each gas in
the mixture.
REFERENCES:
http://www.craigmossonline.net/Public/Dive/scubaexpl.pdf
https://www.carolina.com/teacher-resources/Interactive/scuba-diving-and-gas-laws/tr29802.tr
http://scubatechphilippines.com/scuba_blog/scuba-gas-laws-for-diving-physics/
https://oceanexplorer.noaa.gov/edu/lessonplans/gaslaws.pdf
https://www.globalsecurity.org/military/library/policy/army/fm/20-11/chap07.pdf
https://www.researchgate.net/publication/257025316_Fundamentals_of_scuba_diving_physics
https://www.leisurepro.com/blog/scuba-guides/scuba-diving-essential-things-need-bring/
BAGUIO SEVENTH-DAY ADVENTIST SCHOOL
“The School that leads to Jesus”
#46 Bokawkan Road, Baguio City
Submitted to:
Dary Fabito
General Chemistry Teacher
Submitted:
On October 16, 2019
by Krizelle Mae Barongan
G12 Student
2nd Grading Period: 1st Semester