Exam (elaborations) PADI IDC

Recreational diving Diving no deeper than 130 feet (40 metres) with the no stop limits of recognized dive tables or dive computers. Must be within 40 metres/130 feet of the surface or within sight of light from the surface if diving in overhead environment. No Stop Limit the max time you can stay at a given depth and still ascend directly to the surface without making a decompression stop (aka no decompression limits or NDL) Decompression sickness "the bends" - a condition caused when gas bubbles form in the body after a dive a pause or pauses in ascent at a specific depth and time Decompression stop to allow the body to release dissolved gas and avoid decompression sickness Safety stop a pause in ascent, usually at 15 feet (5 metres) that is not required but made for added conservatism to further reduced chances of decompression sickness PADI Professional Association of Diving Instructors; established in 1966 Deep Dive 100 feet (30 metres) or deeper PADI Master Scuba Diver PADI Junior Certifications PADI Rescue Diver who has earned 5 specialties. 10 years old or older can earn PADI junior OWD certification and those 12 years and older can be come junior AOW and junior RD. Same requirements as adult certs but require diving with an adult and some additional limits until the diver reaches the age of 15. PADI Seal Team and Bubblemaker 8 years and older can scuba dive in a pool or shallow confined water area with pool- like conditions. Bubblemaker status allows kids to experience scuba 1/10 / 7/12/25, 10:13 PM PADI IDC / 2/1 0 diving but Seal Team offers a series of pool activities that build skills that transfer to PADI junior OWD. Subdivisions of Tec Diving Deep diving; trimix diving; cave diving; technical wreck diving; technology-specific diving Tec Diving definition 1) diving more than 130 feet (40 metres); 2) required stage decompression; 3) diving in overhead environment beyond 130 feet; 4) accelerated decompression; 5) use of different gas mixtures on single dive Hang time slang for time required for decomp stops Accelerated decompression Switching to gas blends high in oxygen, or pure oxygen, to shorten the required decompression time Trimix gas blend consisting of helium, oxygen, and nitrogen; the helium offsets narcotic properties of nitrogen at deep depths Enriched air nitrox gas blend consisting of nitrogen and oxygen, with the proportion of oxygen higher than 21 percent; used to accelerate decompression in tec diving oxygen toxicity convulsions caused by oxygen at depth; safe limits determined by the proportion of oxygen in the gas and the depth CCR closed-circuit rebreather, a form of scuba that is more efficient because it recycles exhaled gases instead of releasing them as bubbles hit to suffer oxygen toxicity or decompression sickness Technical deep diving Dives deeper than 130 feet typically requiring decompression stops; training focuses on equipment, calculations, and using different gas blends. Qualifies divers to dive as deep as 165 feet. Trimix diving In ideal conditions, divers use a mix of helium, nitrogen, and oxygen for dives deeper than 165 feet. No set depth limit, but newly certified trimix divers set depth limits to 245 feet (75 metres). Cave diving Typically shallower; main danger is far from air/light source and stirring up silt. Sidemount diving Typically used in cave diving; divers ear separate 7/12/25, 10:13 PM PADI IDC / 3/1 0 cylinders on one or both sides, which allows for movement through very small areas more easily. Technical wreck diving Entering the structure of a sunken ship and penetrating beyond 130 linear feet from the surface Technology-specific diving Includes training with long-distance diver propulsion vehicles or CCRs NAUI National Association of Underwater Instructors John Cronin Scuba manufacturer rep who co-founded PADI Ralph Erickson swim coach and scuba instructor who co-founded PADI Benoit Roaquayrol Developed first open circuit demand scuba in 1865 with Auguste Denayrouze Auguste Denayrouze Developed first open circuit demand scuba in 1865 with Benoit Rouquayrol Henry A. Fleuss In 1879, he developed first practical working scuba - an oxygen rebreather that did not differ much from modern oxygen rebreathers. Louis Boutan Took first underwater photographs by a diver in 1892. John Scott Haldane Published first dive tables in 1908. Louis de Corlieu Invented first rubber fins for swimming in 1933. Emile Gagnan Co-developed the open circuit compressed air regulator with Jacques Cousteau in 1943. Conshelf I Founded by Jacques Cousteau, the project entailed two divers spending 1 week in 33 feet of water. Conshelf II Five divers lived at 36 feet for one month in the Red Sea. Phil Nyutten Patented oil-filled rotary joint for hard suits, which becomes the basis of the Newt Suit. Raymond E. Rogers Developed the Recreational Dive Planner Atomic mass total mass of particles in atom Atomic number number of protons in an atom Isotopes Atoms of an element that have a different number of neutrons (but same number of protons) Molecular elements compounds that consist entirely of atoms from a single element Reactive (chemistry) An atom with an electron formation that allows it to form a chemical bond; reactivity depends on the number of electrons in its outermost shell. Stable (chemistry) An atom that has the max number of electrons in its outermost shell and will not react with other atoms. Examples of this are the inert gases such 7/12/25, 10:13 PM PADI IDC / 4/1 0 as helium and neon. Ionic bonding One atom takes an electron from another atom to complete its outer shell (e.g. NaCl) Covalent bonding Atoms share electrons to complete their outer shell (e.g. water) Pressure (related to diving) Pressure we experience from the atmosphere and while diving is the force of gravity acting on air and water. Atmospheric pressure is the weight of the air above you and water pressure is the weight of the water above you - the water is pulled down by gravity. Weight a measure of the force of gravity acting upon mass Mass mass is a measure of matter based on the matter's inertia; can be used interchangeably with weight in diving because we only ever dive on earth... Work application of a force through a distance Energy the capacity to do work Polar Structure of Water Negative charge at the oxygen end and slight positive charge at the hydrogen end; the polarity causes water molecules to create a hydrogen bond (or polar bond) with each other Surface Tension of Water Polar bonds between water molecules make the water surface slightly cohesive, so it resists penetration and separation. Solubility in Water The universal solvent; molecules begin to interact according to their polarity. Ionic substances are ripped apart and remain suspended within water Nonpolar molecules don't readily dissolve in water. Oils and fats are nonpolar. Heat Capacity A measure of the amount of heat that must be added or removed from a substance to make it change temperature a given amount. 7/12/25, 10:13 PM PADI IDC / 5/1 0 Water and heat capacity Water's polar structure gives it one of the highest heat capacities of all naturally occurring substances. When heating water, a significant amount of heat energy must first break the bonds before heat can increase the kinetic energy (temp) of the water molecules. For the same reason, water also has a high heat of vaporization and high latent heat of fusion ( when water freezes, it releases large quantities of heat).