Deep sea diving and operating submarines present many hazards and dangers. Divers and submariners must carefully control their buoyancy to navigate underwater. Changes in water pressure at different depths can cause injuries, and ascending too quickly can cause decompression sickness as gases in the body expand rapidly. Life support systems work to maintain breathable air, remove carbon dioxide, and control temperature and humidity within submarines and diving suits. Precise navigation is also required as crews rely on inertial guidance and sonar systems while underwater.

1. A PRESENTATION ON PERILS
OF DEEP SEA DIVING
BY
ABHISHEK KUMAR

2. Scuba: acronym for self contained underwater
breathing apparatus.
Scuba Diving : form of underwater diving in which a diver
uses a scuba set to breathe underwater.

3. TYPES OF SCUBA DIVING
•Personal
•Professional

4. PERSONAL
• cave diving
• wreck diving
• ice diving
• deep diving

5. PROFESSIONAL
• Military Diving
1. Direct Combat
2. Infiltration behind enemy lines
3. Placing mines
4. Engineering operations
5. Civilian operations
6. Rescue operations

6. EQUIPMENTS

8. TERMS CONTD..

10. night.

12. MECHANISM
Diving suits made of compressible materials, decrease in volume as
the diver descends, and expand again as the diver ascends, creating
buoyancy changes.
The diver can inject air into dry suits to counteract the compression
effect and squeeze.
Buoyancy compensators allow easy and fine adjustments in the
diver's overall volume and therefore buoyancy.

13. HAZARDS & DANGERS
Weight of the water column above the diver causes an
increase in pressure in proportion to depth.
Variation of pressure with depth cause compressible materials
and gas filled spaces to tend to change volume, which can
cause the surrounding material or tissues to be stressed, with
the risk of injury if the stress gets too high.

14. HAZARDS & DANGERS contd..
• Pressure injuries are called barotrauma and can be quite
painful, even potentially fatal - in severe cases causing a
ruptured lung, eardrum or damage to the sinuses.
Increased amounts of non-metabolic gases(usually nitrogen
and/or helium) dissolving in the bloodstream will
accumulate until saturated.

15. HAZARDS & DANGERS contd..
When the pressure is reduced during ascent, the amount of
dissolved inert gas that can be held in stable solution in the tissues is
reduced
The dissolved gas will be diffused back from the bloodstream to the
gas in the lungs and exhaled stable solution in the tissues is reduced.
The reduced gas concentration in the blood has a similar effect when
it passes through tissues carrying a higher concentration, and that
gas will diffuse back into the bloodstream, reducing the loading of
the tissues.

16. HAZARDS & DANGERS contd..
Reversible alteration in consciousness producing a state similar to
alcohol intoxication in divers who breathe high pressure gas at
depth.
Cause: toxic effect of high nitrogen pressure on nerve conduction.
Mechanism similar to anaesthesia and can be feel at a depth of 40m.
Symptoms: Euphoria, anxiety, loss of coordination and lack of
concentration.

17. HAZARDS & DANGERS contd..
occurs when oxygen in the body exceeds a safe partial pressure
result in the diver spitting out his regulator and drowning
Effects: cough, pneumonia, permanent lung damage, muscular
twitching, vomiting, dizziness, vision or hearing abnormalities.
For deep dives—generally past 180 feet (55 m), divers use "hypoxic
blends" containing a lower percentage of oxygen than atmospheric
air.

19. SUBMERSIBLES
• small vehicle having shorter range(10km below the surface)
designed to operate underwater.
• supported by a surface vessel, platform, shore team or
sometimes a larger submarine.
• hold only a small crew, and have no living facilities.
Technologies involved in design:
Single atmosphere submersibles:
• contains pressurized hull & occupants are at standard
atmospheric pressure.
Ambient pressure technology:
• maintains the same pressure both inside and outside the
vessel. This reduces the pressure that the hull has to withstand.

20. Wet Sub Technology:
• refers to a vehicle that may or may not be enclosed, but in either case
water floods the interior
• SCUBA equipment is used to facilitate breathing.
Deep-diving manned submersibles:
• Bathyscaphe Trieste reach the deepest part of the ocean(nearly
11km)below the surface, at the bottom of the Mariana Trench in
1960.
• China(Jiaolong project in 2002)The Jialong submersible was
designed to reach depths of up to 7,000 meters below sea level and
is expected to have a 7,000-meter test dive in 2012.
• DSV Alvin, which takes 3 people to depths of up to 4,500 metres
(14,800 ft).

21. Commercial submersibles
• small submersibles for tourism, exploration and adventure travel.
ROVs
• Small unmanned submersibles called "marine remotely operated
vehicles" or MROVs
• Used to work in water too deep or too dangerous for divers.
• Remotely operated vehicles (ROVs) repair offshore oil platforms
• The wreck of the Titanic was explored by such a vehicle, as well as by
a manned vessel.

22. SUBMARINES
• A submarine(large crewed autonomous vessel) is a watercraft capable of independent
operation underwater.
• It differs from a submersible, which has more limited underwater capability.
MECHANISM
• Weight of water displaced is equal to the weight of the ship. This displacement of water
creates an upward force called the buoyant force and acts opposite to gravity .
• Unlike a ship, a submarine can control its buoyancy, thus allowing it to sink and surface at
will.
Controlling buoyancy
The submarine has ballast tanks and auxiliary, or trim tanks, that can be alternately filled with
water or air (see animation below). When the submarine is on the surface, the ballast tanks are
filled with air and the submarine's overall density is less than that of the surrounding water. As
the submarine dives, the ballast tanks are flooded with water and the air in the ballast tanks is
vented from the submarine until its overall density is greater than the surrounding water and
the submarine begins to sink (negative buoyancy). A supply of compressed air is maintained
aboard the submarine in air flasks for life support and for use with the ballast tanks.

23. MANOUVERING
Hydroplanes:
• movable sets of short "wings" called hydroplanes on the stern (back)
that control the angle of the dive.
• Angled so that water moves over the stern, which forces the stern upward;
therefore, the submarine is angled downward.
Life support
Maintaining the Air Quality
A submarine is a sealed container that contains people and a limited
supply of air.
• Oxygen is supplied either from pressurized tanks(oxygen generator
or some sort of "oxygen canister" )that releases oxygen by a very
hot chemical reaction.
• Carbon dioxide can be removed from the air chemically using soda
lime (sodium hydroxide and calcium hydroxide) in devices called
scrubbers.

24. • The moisture can be removed by a dehumidifier or by chemicals.
• Filters are used to remove particulates, dirt and dust from the air.
Maintaining a Fresh Water Supply
• Distillation apparatus that can take in seawater and produce fresh water.
• Water is used mainly for cooling electronic equipment and for supporting the crew.
Maintaining Temperature
• Electrically heated to maintain a comfortable temperature for the crew.
• Electrical power for the heaters comes from the nuclear reactor, diesel engine, or batteries
(emergency).
Navigation
• Equipped with navigational charts and sophisticated navigational equipment.
• Underwater, the submarine uses inertial guidance systems (electric or mechanical)
• The inertial guidance systems are accurate to 150 hours of operation and must be realigned
by other surface-dependent navigational systems (GPS, radio, radar, satellite).
• Range of operation is within a hundred feet of its intended course.
• To locate a target, a submarine uses active and passive SONAR (sound navigation and
ranging).