Self Contained Underwater Breathing Apparatus SCUBA Diving Self Contained Underwater Breathing Apparatus

PADI Open Water Course Course Requirements must be completed for certification Knowledge development- completed before pool Read PADI manual, complete worksheet, Video and quiz for all 5 chapters Pass PADI final exam 2 pool practice sessions 4 ocean dives, 2 per day

PADI Section 1 Being a Diver 1

Water Pressure and Air Volume At Sea level the weight of the atmosphere above us exerts a pressure of 1 Atmosphere (14.7 psi) on us Water is heavier than air so it only takes 33 feet of water to equal 1 ATM of pressure At 33 feet under water you are at a pressure of 2 ATM, 1 from the atmosphere and 1 from the water above you Pressure increases by 1 ATM every 33 feet(10 meters)

Water Pressure and Air volume

Depth, Pressure and air Density

Depth, Pressure and Surface Equivalent

Increasing Pressure and Body Air Spaces Body air spaces include Lungs, inner ear, sinuses and mask and possibly teeth fillings To equalize your ears and sinuses pinch your nose and blow gently against it To equalize your mask exhale out your nose adding air to the mask If you cannot equalize stop your descent immediately, signal your buddy or instructor An unequalized air space is called a squeeze

Equalization of Air Spaces Ascend slightly until discomfort passes and try again, after you equalize descend slower and equalize more often Continuing to descend with unequalized air spaces can lead to dammage to the eardrum An unequalized mask can cause bruising around the eyes If you cannot equalize stop the dive

Equalization of Air Spaces Never attempt a forceful or extended equalization Use short gentle, frequent equalizations Never dive with a cold or allergy, congestion can block sinuses and air passages Cold medications can wear off during a dive Never use ear plugs or goggles while diving

Equalization of Air Spaces Lung equalization is accomplished by normal continuous breathing Skin (Breath Hold) Diving poses special problems, do not descend after exhaling or breath hold diving deeper than 200 feet Do not Dive with lung congestion which can trap air

Effects of Decreasing Pressure on Air Spaces Air pressure decreases during ascent Expanding air must exit the body This happens naturally in your ears, sinuses and mask Expanding air in your lungs is most important Normal breathing while ascending will release expanding air from your lungs Never Hold your breath While on SCUBA

Effects of Decreasing Pressure on Air Spaces Most Important Rule in SCUBA is Always Breath Lung over expansion can happen in as little as 3 feet, a slight pressure change Lung over expansion injuries are difficult to treat and can cause paralysis and death by forcing air into the blood stream and chest cavity Anytime the regulator is not in your mouth exhale a slow steady stream of bubbles

Effects of decreasing Pressure on Air Spaces Reverse Blocks result when expanding air becomes trapped in a body air space Reverse blocks can occur when diving with a cold or allergy or using cold medicine Gas can form in the stomach or intestine and may take time to pass A tooth squeeze is rare but can happen if air is trapped under a filling If you feel discomfort on ascent, stop descend a few feet, give the air time to escape and ascend slower

Breathing Underwater Pressure increases with depth and decreases air volume Density of air increases as volume decreases Each breath fills the same lung volume so more air is needed to fill each breath The deeper you are the faster you use air A tank of air that lasts 1 hour at 0 feet will last ½ hour at 33 feet (10 meters)

Buoyancy Buoyancy of an object is dependent on the weight of the object compared to the weight of the water displaced by the object Three types of Buoyancy positive, neutral and negative The Buoyancy compensator device allows us to change our buoyancy as needed The weight system allows us to overcome the bodies natural Buoyancy

SCUBA Equipment

PADI Section 2 Being a Diver 2

Section 2 Water is 800 times denser than air which causes many differences between terrertrial and aquatic worlds Magnification- underwater everything looks 1/3 larger which causes it to look closer Color loss occurs as you go deeper, red, yellow and orange penetrate the least, Blue, green and purple penetrate the deepest Underwater sound travels 4x faster and greater distances, we cannot tell the direction it is coming from

Swimming and Moving Because of waters density streamlining is very important to reduce drag and save energy Increasing your speed while swimming requires 4 times more energy and air consumption Trim your body position so feet and head are approximately level by placing the correct amount of weight and appropriate position

Staying Warm Water absorbs heat 20 times faster than air, you can chill rapidly in water 86 degrees Hypothermia is a serious condition, uncontrolled shivering means end the dive and exit the water immediately An appropriate exposure suit, wet or dry suit will keep you comfortable while diving Wet suits work by absorbing water which your body heats and retaining that water so you do not have to reheat new water

Wet Suits

Dry Suits

Breathing Effectively Underwater Because of the increased density of the air we breath while Diving slow deep breathing requires less effort Deep breathing is more efficient at exchanging gases O2 and CO2 in our lungs Deeper breathing minimizes the dead air spaces in our throat and equipment Airway control is the skill of breathing with residual water in our regulator or snorkel without drawing any into your throat

Managing Your Air Supply On shallow dives air supply is usually the limiting factor Plan or returning to the boat with 500 psi remaining in your Tank as a reserve A safety stop at 15 ft for 3-5 min requires 300 psi (totals 800psi) reserve and safety If your starting pressure is 3000 psi minus 800psi you have 2200 psi to dive with so 1100 psi out and 1100 back

Managing Your Air cont. Plan your air management based on who has the least air On deeper dives (ship wrecks) plan on leaving the bottom with 1000 psi in tank As you ascend to shallower depth you use air at a much slower rate “Do not risk running out of air underwater” ascend where you are and swim on surface

Deep Wreck Diving

Buddy System Number two rule in SCUBA Diving “Never Dive Alone” Buddy System- Two or more divers working together for convenience, safety and fun Plan the dive and then Dive the Plan Agree on entry and exit points, course to follow, depth and time limits, signals and communication, turn around point, who leads and who follows, separation procedures

Buddy system cont. Predive safety check- begin(BC)- with(weights) - review(releases) – and(air)- friend(final OK) Buddy separation procedures- look for no more than one minute 360 degrees on bottom then surface and reunite on the surface and descend together On deep shipwreck meet at anchor/ascent line It is Your responsibility to stay together

Buddy System

Buddy System

PADI Section 3 Being a diver 3

Section 3 Dive environments and conditions vary world wide and by season and assessing these can affect your dive plans Besides season water depth can affect temperature, the deeper you go the colder it can get, wear an appropriate exposure suit Visibility can range from 0 to 200 feet and is affected by water movement, weather, plankton and bottom composition

Water Movement Two types of water movement affect diving, waves and current The stronger the wind the larger the waves, smaller waves 1-3 feet seldom affect diving but larger waves require more experience and may prevent diving Currents are a result of waves, tides, heating and cooling water and the earths rotation Begin your dive into or against the current, when you head back the current will assist you

Water Movement cont. Currents tend to be strongest at the surface, swim along the bottom where the current is generally weaker If you miss your exit point or boat swim across the current rather than directly into it, there is generally a trail (tag) line off the back of the boat If you cannot get to the boat, establish buoyancy, fill your BC or drop weights and signal the boat to pick you up

Trail ( Tag ) Line

Diving in Current

Dive Boat

Descending Mooring/ Anchor Line

Bottom Composition Bottom composition types-silt/mud, sand, rock, coral, vegetation Bottom composition may be multiple types at a dive site Avoiding bottom contact keeps visibility clearer and avoids hazards like cuts or scrapes Aquatic organisms may be fragile and damaged if touched Stay neutrally buoyant and only touch insensitive bottoms if necessary

Assessing Conditions You are responsible for your own safety and you will be part of the final decision on making the dive One of the skills you will develop as a diver is assessing conditions weather, water motion, visibility, reports online and reports from other divers An area orientation dive will help you become familiar with local conditions, hazards and points of interest

Diving Limits Dive within your personal physical limits and scope of training Failure to do so can lead to incidents and accidents Risks are not always obvious Exceeding limits give false security as having “got away with it” Some anxiety about the dive can affect focus and miss potential problems

Aquatic life Observing aquatic life is one of the main attractions of diving but some pose potential problems, interactions should be passive. Organisms that sting/puncture- jellyfish, portuguese man-o-war, lion and scorpion fish, stingrays, sea urchins, cone shells. Organisms that bite-moray eels, trigger fish, sharks, barracuda and other fish, snakes, octopus, clawed lobster and crabs

Aquatic Life cont. Passive and active interactions, generally passively observing marine life is best for all Active interactions when the animal initiates the interaction is reasonable Feeding marine life can create problems, better left to professionals

Marine Life

Shark Feeding

Aquatic Animal Injuries Be familiar with hazardous organisms in the local environment Avoid wearing shiny dangling jewelry Watch where you put your hands, knees and feet, avoid bottom contact if possible Be cautious in murky water, animal may mistake a diver for prey in poor visibility Usually very pretty or very ugly organisms who do not try to escape are dangerous

Aquatic Animal Injuries Even dead organisms or detached body parts can still sting, puncture Be prepared to provide first aid and CPR Use vinegar on jellyfish and fire coral stings Immerse stings from fish spines in hot 120 degree water 30-90 min Remove sea urchin spines with forceps without breaking them, otherwise for medical personnel

Aquatic Animal Injuries Treat bites by controlling bleeding, bandaging Seek emergency medical care for bites that result in severe reactions, or large ones that do not respond to treatment You can learn more in the PADI Rescue Diver course and the Emergency first Response primary Care (CPR) and Secondary Care (First Aid) courses

Lion Fish

Portuguese Man o war

Fire Coral

Stone Fish

Sea Urchin

Shore Diving Most environments offer shore diving Put on your equipment except your mask, snorkel and fins Put mask on just before entering water and don you fins in waist to chest deep water Leave BC empty to keep weight on your feet As you enter surf turn sideways and bend knees to brace yourself against wave

Shore Diving cont. Surge is the back and forth motion of the wave underwater, bigger waves have deeper surge, Dive deeper below the surge Undertow is the wave running back down the slope of the beach, may undermine your footing, if you fall just crawl out Rip currents form from water pushed over a sandbar and move back through available openings, you can see a break in the incoming waves

Rip Currents

Rip Current

Boat Diving Most diving is done from boats to avoid long surface swims You can dive from large charter boats or something as small as a kayak Use a Gear bag to organize your equipment, bring clothes, beverages, snacks Seasickness can be addressed with motion sickness medicine, look at the horizon, keep the wind in your face

Boat Terminology Bow – front of boat (forward) Stern- back of boat (aft) Starboard- right side of boat Port- left side of boat Head- Toilet Facilities Galley- kitchen Bridge- where the boat is driven from Swim Platform-extension from stern for entering and exiting water

Dive Boats

Dive Boats

Dive Boat Ladder

Boat Diving Entry Giant Stride entry from platform BC jacket 1/3 full air Real toes up to edge of platform Check that area is clear then Look straight out Right hand on mask/regulator left hand on releases Hoses for SPG and Alternate Regulator collected inside elbows Pick up leading edge of fin as you step

Boat Diving Exits Follow directions of divemaster on boat Hang onto tag line on surface until it is your turn, stay clear of ladder Remove fins while holding tag line/ ladder and hand up to divemaster Both hands and feet on ladder, one step at a time/ two feet one step Keep mask on and regulator in mouth in case you fall back in

Problem Management SCUBA diving comes with some risks and potential problems from being in water and breathing compressed air Your knowledge and training will help you to manage and avoid problems and control risks Additional diver training and experience improves your ability to manage problems PADI advanced open water course gives you additional training under supervision

Problem management PADI rescue diver course covers dive emergency training with hands on practice Emergency first response primary and secondary care courses teach you CPR and First Aid PADI Emergency Oxygen provider qualifies you to administer Oxygen in medical emergencies

Problem Management Assisting Divers at Surface Most Diver in distress problems occur at the surface Dive within your limits Relax while you dive Plan your use of air Establish buoyancy Stop, Think, Act Asking for Help when you have a small problem avoids a big problem

Problem Management Assisting Divers Free flowing regulator- hold regulator up to lips and sip air from regulator, let excess air escape, head to surface Entanglement- stop, think work calmly to free yourself, avoid turning or twisting, use cutting tool if necessary, you may slip out of SCUBA kit to free it Overexertion- most common underwater problem, pace yourself breath slowly/ deeply

Running Low On/ Out of Air underwater 1 Make a normal ascent- cylinder is not completely empty, as you ascend you get more air from your cylinder 2 Ascend using alternate air source- Best choice when an alternate air source is available, stay close to your buddy

Running Low On/ Out of Air underwater 3 Controlled Emergency Swimming Ascent- completely out of air and no deeper than 30 ft. Buddy is too far away. Look up and swim to the surface making an aaah sound to exhale expanding gas. All gear stays in place, control your rate of ascent 4 Buoyant Emergency Ascent- deeper than 30 ft same procedure as emergency swimming ascent except drop your weight belt, near surface flare arms and legs to slow ascent

Problem Management Assisting Divers Unresponsive Diver at surface- establish buoyancy for both divers, check breathing and begin rescue breaths while towing, call for help from boat Unresponsive Diver underwater- make victim buoyant, hold regulator in mouth if already there, swim victim to surface, ascend at a safe rate, check breathing at surface

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