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JCA Elite Scuba Advanced Nitrox Program
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7.1 Introduction This course examines the use of EAN-21 through 100 percent oxygen for optimal mixes to a depth of 130 feet. The objective of this course is to train divers in the benefits, hazards and proper procedures for utilizing EAN-21 through 100 percent oxygen for dives not requiring staged decompression. TDI Decompression Procedures or the Intro to Tech may be combined with this course at the discretion of the instructor. 7.2 Qualifications of Graduates Upon successful completion of this course, graduates may engage in diving activities utilizing EAN-21 through 100 percent oxygen without direct supervision provided: 1. The diving activities approximate those of training 2. The areas of activities approximate those of training 3. Environmental conditions approximate those of training Upon successful completion of this course, graduates are qualified to enroll in: 1. TDI Decompression Procedures Course 2. TDI Extended Range Course CHAPTER 1 OVERVIEW
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7.5 Student Prerequisites 1. Minimum age 18 2. Minimum certification of TDI Nitrox Diver, or equivalent 3. Show proof of 25 logged open water dives TDI Instructor Manual Diver Standards Standards 4. If this course is taught in conjunction with the TDI Decompression Procedures course, the minimum age is 18 Procedures course, the minimum age is 18 7.6 Course Structure and Duration Open Water Execution 1. Four dives are required with a minimum accumulated bottom time of 100 minutes 100 minutes 2. If advanced nitrox is taught in conjunction with decompression procedures*, only a total of 6 dives are required, more may be procedures*, only a total of 6 dives are required, more may be conducted at the discretion of the instructor, with a maximum depth of conducted at the discretion of the instructor, with a maximum depth of 130 feet 130 feet 3. If Advanced Nitrox is taught in conjunction with Intro to Tech*, only a total of four (4) dives are required, more may be conducted at the total of four (4) dives are required, more may be conducted at the discretion of the instructor, but all dives must be conducted at depths discretion of the instructor, but all dives must be conducted at depths within the diver’s current level of certification and no dives should within the diver’s current level of certification and no dives should exceed 75 feet exceed 75 feet
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7.9 Required Equipment The following equipment is required for each student: 1. Alternative second stage octopus attached to a primary regulator or a redundant scuba unit, 30 cu ft minimum, SPG, removable staging setup 2. A submersible pressure gauge 3. Depth gauge or bottom timer AND dive computer OR two dive computers 4. Buoyancy compensator device (BCD) with power inflator with at least 40lbs of lift 5. 2 Line cutting devices (scissors, knife, line cutter, light saber, etc) 6. Exposure suit adequate for the open water environment 7. Cylinder and regulator properly labeled and cleaned as required for EAN mixtures appropriate size for dives conducted using rule of thirds 8. Access to oxygen analyzer, may be supplied by instructor 9. Wrist slate (multi-page preferred) 9. Wrist slate (multi-page preferred) 10. SMB or lift bag with at least 50lbs of lift 10. SMB or lift bag with at least 50lbs of lift 11. Reel or finger spool with at least 100ft of line 11. Reel or finger spool with at least 100ft of line 12. Access to air dive tables, air decompression dive tables, dive decompression software, dive planning software, gas management software 12. Access to air dive tables, air decompression dive tables, dive decompression software, dive planning software, gas management software
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7.10 Required Subject Areas The TDI Advanced Nitrox Manual is mandatory for use during this course but instructors may use any additional text or materials that they feel help present these topics. The following topics must be covered during this course: 1. Physics a. Pressure review 2. Physiology a. Hypoxia b. Oxygen toxicity i. Whole body oxygen toxicity units (OTU’s) ii. Central nervous system (CNS) c. Nitrogen narcosis d. Nitrogen absorption and elimination e. Carbon dioxide toxicity f. Carbon monoxide toxicity 3. Formula Work a. Best mix computations b. Maximum operating depth (MOD) of mixture computations
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4. Equipment Considerations 4. Equipment Considerations a. Less than 40 percent oxygen content b. More than 40 percent oxygen content 5. Dive Tables a. Equivalent air depth with any table b. Computer generated tables 6. Dive Computers a. Mix adjustable b. Oxygen (O2 )integrated 7. Dive Planning a. Operation planning i. Gas requirements ii. Oxygen limitations iii. Nitrogen limitations 8. Common Mixing Procedures a. Partial pressure blending b. Continuous blending c. Membrane separation system 9. Decompression 9. Decompression a. Enriched air nitrox (EAN) usage as a decompression gas (i.e. 50/50, 80/20, etc) (i.e. 50/50, 80/20, etc) b. Oxygen (O2) for decompression c. Advantages / disadvantages of multiple gas switches
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7.11 Required Skill Performance and Graduation Requirements Maximum training depths shall not exceed 130 feet. The following open water skills must be completed by the student during all open water dives: Land Drills 1. Review of nitrox skills 2. Demonstrate correct use of oxygen analyzer including optimal procedure for calibration calibration 3. Demonstrate adequate pre-dive planning a. Limits based on personal gas consumption. b. Limits based on oxygen exposures at planned depth with actual mix c. Limits based on nitrogen absorption at planned depth with actual mix 4. Calculate and log CNS loading for each dive including cumulative exposure where appropriate where appropriate 5. Demonstrate understanding of gas labeling 6. Demonstrate adherence to conventions regarding prep of equipment for oxygen (O2) service (O2) service 7. Program nitrox computer with appropriate oxygen percentage if used 8. Properly execute the planned dive within all predetermined limits
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In order to complete this course, students must: 1. Satisfactorily complete the TDI Advanced Nitrox course written examination 2. Complete all open water requirements safely and efficiently 3. Demonstrate mature, sound judgment concerning dive planning and execution execution Pre-dive Drills 1. Use START* before every dive 2. Stress analysis and mitigation *START is S-drill (OOA drill and Bubble Check), Team (buddy equipment checks), Air (gas matching), Route (entry/exit and planned path underwater), Tables (depth, duration, way points and schedule). In-water Drills 1. Demonstrate buoyancy control; ability to hover at fixed position in water column without moving hands or feet without moving hands or feet 2. Show good awareness of buddy and other team members through communications, proximity and team oriented dive practices communications, proximity and team oriented dive practices 3. Demonstrate ability to manage free flow from primary regulator in controlled fashion, shutdown cycle, and switch to back-up regulator fashion, shutdown cycle, and switch to back-up regulator 4. Conduct appropriate safety stop while maintaining neutral buoyancy 5. Demonstrate ability to share air with buddy as both recipient and donor in a controlled manner while maintaining position in water column controlled manner while maintaining position in water column 6. Demonstrate correct body position; appropriate trim, such as horizontal / streamlined when moving forward streamlined when moving forward 7. Demonstrate proper stress analysis with self and dive buddy
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CHAPTER 2 TECHNICAL DIVING MINDSET Dive planning “plan your dive, dive your plan” being in control What is “being in control?” START S-drill, (OOA and Bubble Check), Team (buddy equipment checks), Air (gas matching), Route (entry/exit and planned path underwater), Tables (depth, duration, way points and schedule) Gas planning gas management How do you know how much gas you have? gas consumption RMV ( Respiratory Minute Volume) SAC (Surface Air Consumption) RMV and SAC Calculators RMV and SAC Calculators Equipment configuration GUE, DIR, WTFC trimstreamlining consistent placement EXERCISE
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Experiences while diving interacting with the environment where your body is in reference to where you're diving changes in the environment thermoclines, haleoclines, silt up's, site changes Dive objectives tasks and task loading task priorities changes in priorities and plans Environmental awareness tides and currents open water ascents and deco obligations Thermal considerations water temperature, length of dive, deco obligations Visit sites UNION, HOOD CANAL, WA Stationid: 9445478 NOAA Tides & Currents Map
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Situational awareness entanglement hazards equipment failures equipment loss lost buddies carrying versus staging Propulsion through the water fining techniques modified frog, frog, modified flutter in current and/or in surge Buoyancy Control staying off the bottom while multitasking with loss of equipment or equipment failures Breathing breath control breathing techniques inhalation versus exhalation
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CHAPTER 3 GASES Oxygen life sustaining gas too little or too much is not good Air compound primarily composed of oxygen (0 2 ) and nitrogen (N 2 ) Relevant Gas Laws Boyle'sDalton'sCharles'Gay-Lussac's Boyle’s Law (pressure/volume) P 1 V 1 = P 2 V 2 = P 3 V 3, etc... Boyle's law states that the volume of a given amount of gas held at constant temperature varies inversely with the applied pressure when the temperature and mass are constant. Can be used to calculate how much gas you will need for your dive RMV#1 and SAC#2 (#1=ft3/minute / #2=psi/minute) how much gas you need versus how much gas you use
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Dalton’s Law (partial pressures) Ptotal = Pa + Pb + Pc +... Dalton's Law states that the total pressure of a mixture of non-reacting gases is the sum of their individual partial pressures. Can be used to calculate MOD MOD (Maximum Operating Depth) MOD (fsw) = 33ft x [ (PO2/FO2) – 1 ] Charles' Law (volume/temperature) V 1 / T 1 = V 2 / T 2 = V 3 / T 3 etc... This law states that the volume of a given amount of gas held at constant pressure is directly proportional to the Kelvin temperature. Gay-Lussac's Law (pressure/temperature) P 1 / T 1 = P 2 / T 2 = P 3 / T 3 etc... This law states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature.
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CHAPTER 4 GAS PHYSIOLOGY Hypoxia Hypoxia is too little oxygen. Life cannot be sustained without enough oxygen. The brain will begin to not function properly and if continued, unconsciousness will occur. 16% is typically recognized as the lower threshold where hypoxia will begin. At what depth are the FO 2 's of 16%, 17%, 18%, and 19% close to 21% ? [ ( D / 33) ] * FO 2 + FO 2
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depth in feet16%17%18%19% 00.160.170.180.19 10.16480.17520.18550.1958 20.16970.18030.19090.2015 30.17450.18550.19640.2073 40.17940.19060.20180.2130 50.18420.19580.20730.2188 60.18910.20090.21270.2245 70.19390.20610.2182 80.19880.21120.2236 90.20360.21640.2291 100.20850.2215 110.2133 120.2182 130.2230 330.320.340.360.38
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Pulmonary Oxygen Toxicity Long exposure to lower partial pressure of oxygen. Effect is cumulative and will not get better until a break from high partial pressure of oxygen is taken. (computer aided monitoring) EXERCISE (go to slide 20) Oxygen Toxicity Oxygen toxicity is too much oxygen in the body. Divers must track oxygen exposure when diving with a higher oxygen gas mix. Both short and long term exposure can cause problems. 1.6 ATA is the accepted maximum exposure level for oxygen. On working, cold or stressful dives the PO 2 should be lowered. When breathing higher partial pressure of oxygen the diver must track their Central Nervous System (CNS) to avoid problems. Oxygen Pressure Time Limits (Minutes) PO2Single Dive% CNS/MinDaily 1.6452.22150
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Oxygen Pressure Time Limits (Minutes) PO2Single Dive% CNS/MinDaily 1.6452.22150 1.51200.83180 1.41500.67180 1.31800.56210 1.22100.48240 1.12400.42270 1.03000.33300 0.93600.28360 0.84500.22450 0.75700.18570 0.67200.14720
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Single Dive verses Multi Dives and Days Track CNS and OTUs to prevent problems. Take oxygen breaks during decompression stops. Be conservative with oxygen exposure. EXERCISE (go to slide 22) 1.41500.67180 Oxygen Pressure Time Limits (Minutes) PO2Single Dive% CNS/MinDaily 1.4 /.21 = 6.67 – 1 = 5.67 ATA 5.67 x 33 = 187ft 5 minutes x 0.67 = 3.35% 5/150 =.033x100 = 3.3% 1.4 /.28 = 5.00 – 1 = 4.00 ATA 4.00 x 33 = 132ft 20 minutes x 0.67 = 13.4% 20/180 =.033x100 = 11.1% 3.3%+11.1%=14.4% 25/180 =.1388x100 = 13.89% 1.6 /.50 = 3.2 – 1 = 2.2 ATA 2.2 x 33 = 72.6ft 15 minutes x 0.67 = 10.05% 15/180 =.083x100 = 8.3% 8.3%+14.4%=22.7% 40/180=0.22x100=22.2%
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Carbon Dioxide Toxicity Carbon dioxide toxicity is a by-product of breathing. Breathing is triggered by excess carbon dioxide (CO 2 ). Improper breathing while diving or ill-maintained equipment may cause a build-up of CO 2. Can have a narcotic effect. Can increase decompression risk. Carbon Monoxide Toxicity Carbon monoxide toxicity is caused by exposure from a bad gas source. CO binds to the hemoglobin blood greater than oxygen – 200x greater...!!! Signs and Symptoms of CO toxicity If suspected during dive abort the dive immediately Dull headache, Weakness, Dizziness, Nausea or vomiting, Shortness of breath, Confusion, Blurred vision, Loss of consciousness Nitrogen Concerns Nitrox reduces nitrogen levels in gas mixture. Complete the deep part of dive first. Avoid big swings in depth during the dive. Risk of decompression is always present. Be prepared to handle a Decompression Illness (DCI) situation. Nitrogen Narcosis A feeling of intoxication generally starting at 3.2 ATA of N 2
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CHAPTER 5 FORMULAS Boyle’s Law Dalton’s Law Best Mix Maximum Operating Depth (MOD) Partial Pressure Equivalent Air Depth (EAD)
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V1*P1 = V2*P2 V = volume P = pressure volume 1 = X pressure 1 = 1200 volume 2 = 40 pressure 2 = 2400 CALCULATE V1*P1 = V2*P2 X*1200 = 40*2400 X1200 = 96000 X1200/1200 = 96000/1200 X = 80 Boyle’s Law try these... V1*P1 = V2*P2 (solve for P1) V1 = 60 V2 = 30 P2 = 1200 V1*P1 = V2*P2 (solve for V2) V1 = 25 P1 = 1350 P2 = 2650 V1*P1 = V2*P2 (solve for P2) V1 = 80 P1 =.4 V2 = 20 V1*P1 = V2*P2 (solve for V1) P1 = 1200 V2 = 40 P2 = 2400
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Dalton’s Law Partial Pressure A diver wants to know how much oxygen he will be exposed to if he dives to a depth of 92ft with 33%. Best Mix The same diver wants to know which gas to use if he is going to 88ft at a partial pressure of 1.4 ATA. MOD (Maximum Operating Depth) How deep can a diver go on 28% at 1.6ATA? EAD (Equivalent Air Depth) What is the EAD at 100ft with 40%? Pg Fg P PO 2 (partial pressure of oxygen) Pg (partial pressure of a gas) P (absolute pressure) FO 2 (fraction of oxygen) Fg (fraction of gas) Partial Pressure (oxygen dose) FO 2 * P = PO 2.33*3.79=1.25 ATA Best Mix PO 2 / P = FO 2 1.4/3.66=.38 38% MOD [(Pg/Fg)-1]*33 [(1.6 /.28)-1 ] * 33=155ft EAD [(1-F0 2 )(depth+33) / 0.79] – 33 [(1-.40)(100+33)/0.79]-33=68ft
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Back Gas Aluminum 80 (77.4ft 3) Steel 80 (80ft 3) Steel 100 (100ft 3) Sling Bottles Aluminum 30 (30ft 3) Aluminum 50 (50ft 3) Aluminum 80 (77.4ft 3) Rule of Thirds one third of the gas out one third of the gas back one third reserve How to calculate how much gas to start with back gas needed for dive: 70ft 3 70/2*3=105ft 3 deco gas needed for a dive: 18ft 3 18/2*3=27ft 3 Formula to calculate maximum volume in bottle to use this bottle with rule of thirds 70/3*2=46.67 Tank Basics
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Cylinder baseline calculations Diver #1 Aluminum 80 (77.4ft 3 ) with a working pressure of 3000psi 80/3000=.0267ft 3 per psi if the tank has 2700psi, there is 72.09ft 3 inside Diver #2 Steel 80 (80ft 3 ) with a working pressure of 3500psi 80/3500=.0228ft 3 per psi if the tank has 2700psi, there is 61.56ft 3 inside If each diver has the same RMV, these two tanks will not provide the same volume of gas... the subsequent turn PSI must be calculated EXAMPLE RMV of.50 with an average depth of 66ft will require 1.50ft 3 of gas per minute. If each person needs 40ft 3 of gas for the dive, the turn PSI will be: #1: 40/0.0267=1498/2=749 2700-749=1951 #2: 40/0.0028=1754/2=877 2700-877=1823
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Bailout Procedures RMV and SAC Calculators RMV and SAC Calculators Dive# 1, VPM-B +3 Elevation = 0 ft CNS = 7% OTU's = 22 Gas AIR = 102ft 3 RMV set at 0.50 Decozone start = 72ft gas needed for dive 102/2*3=153ft 3 51ft 3 available for emergency or air sharing
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Dive# 1, VPM-B +3 Elevation = 0 ft CNS = 12% OTU's = 35 Gas AIR = 63ft 3 Gas 50% = 16ft 3 RMV set at 0.50 Decozone start = 72ft gas needed for dive 63/2*3=95ft 3 16/2*3=24ft 3 32ft 3 of AIR available for emergency or air sharing 8ft 3 of 50% available for emergency or air sharing Question, how much extra could a diver carry for contingency if they lost their deco gas? Answer: you can use the “Rock Bottom” amount, but that doesn't leave any for contingencies or higher SAC rate... OR you can do the dive with enough air to deco on air... BUT, you know... what other options could be possible?
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Alternate Answer: instead of each diver carrying a larger volume of AIR to deco off (you'll be in the water a long time by yourself), each carry enough deco gas for both to deco off......instead of carrying only 24ft 3, carry 32ft 3... which is realistic anyway as we'll probably dive with an AL30 or better yet, an AL50 for stress added volume breathed... Dive# 1, VPM-B +3 Elevation = 0 ft CNS = 16% OTU's = 38 RMV set at 0.50 Gas AIR = 69ft 3 Gas O 2 = 7ft 3 Decozone start = 72 ft MOD MAX ON O 2 at 1.6 ATA (7/2*3=10)...stage...??...carry...??
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EQUIPMENT Equipment Cleaning 40% rule Compressor cleaning Cylinder cleaning Regular air use in an O 2 cleaned cylinder COMPUTERS Computer Generated Dive Tables Personal Dive Computers Programmable Dive Computers Carrying a backup computer Desktop Decompression Software PRE-PLANNING Analyze and confirm gas mixture prior to arriving at dive site Proper marking on cylinder GAS BLENDING Partial Pressure Blending Partial pressure blending is the most common method used for blending. Requires properly cleaned equipment Mixing oxygen and air in cylinder Requires slow fill rates Continuous Blending Gas Is mixed before being compressed. Continuous blending is less labor intensive but more equipment intensive. Membrane Separation System Membrane removes Nitrogen from air Allows cylinders to be used that have not been O2 cleaned Premix Supplied by a gas supplier already mixed to specifications
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...thank you
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