JOINT SERVICE ADVENTUROUS TRAINING (JSAT) DIVING

1. JOINT SERVICE ADVENTUROUS TRAINING (JSAT) DIVING DEFENCE DIVING (Mil) CROSSOVER v2

2. Joint Service Adventure Training (JSAT)Sub Aqua Diving BSAC Centres& individual Branches The British Sub Aqua Club The largest Diving Club in the world Formed 1953

3. Chairman • Committee • Members • Diving Officer • Treasurer • Secretary • Training • Officer • Equipment • Officer • Dive • Manager A BSAC Branch • BranchCommittee

4. BSAC Headquarters • Full time Staff • Board of elected volunteer Directors known as • BSAC Council The BSAC - The Organisation • BSAC Members • BSAC Centres • BSAC Branches • BSAC Regional Coaching Team • National Diving Committee • Responsible for diving, instructing and safety standards

5. Benefits of BSAC Membership • Largest Diving Club in the World • Internationally recognised qualifications • Diver Training Materials • Scuba magazine (monthly) • Free Third Party insurance • Member’s Mail Shop • Preferential discounts from equipment and holiday companies

6. Sports Diver • Dive Leader • Advanced Diver First Class (Regional preparation courses and exams) Diver Development within BSAC • Discovery Diver – Reduced training serials than Ocean diver. Qualified to dive to a max of 12m with a Dive Leader under supervision of a Dive Manager • Ocean Diver • Skill Development Courses (SDCs)…

7. Further Branch Training (SDC’s) Technical Twinset diver Accelerated Decompression Procedures Closed Circuit Rebreather (CCR) Diver Mixed Gas SPORT (Open Circuit & CCR) Mixed Gas EXPLORER (Open Circuit & CCR) Mixed Gas ADVANCED (Open Circuit & CCR) Gas Blender (Nitrox) Gas Blender (Trimix) • Branch Diving • Dive UK • Wreck Appreciation • Wreck Diver • Dive Planning & Management • Search & Recovery • Buoyancy & Trim • Drysuit • Compressor Operator • Diving For All Seamanship Boat Handling Diver Coxswain Assessment Chartwork & Position Fixing Outboard Engine & Boat Maintenance Safety & Rescue First Aid for Divers Oxygen Administration Lifesaver Award Advanced Lifesaver Practical Rescue Management Automated External Defibrillator Special Interest Underwater Photography Marine Life Appreciation Ice Diving RNLI Diver Sea-Survival Workshop

8. First Class Diver • National Instr • ExpeditionSADS • Advanced Instr • Advanced Diver • (150+ dives) • BranchSADS • Open Water Instr • Dive Leader • (50+ dives) • Sports Diver • (10-20 dives) • Instructor • Foundation Cse • Ocean Diver • (4 dives) BSAC Diving Grades • British Sub Aqua Club • (National Governing Body) • Military • BRd 2806(5) • Instructor Trainer

9. JSAT Diving • Single Service Association • RNRM SAA • ASADA • RAFSA • L4 JSAT Diving Centres • Joint Service Sub Aqua Diving Centre • Joint Service Adventurous Training Wing (Cyprus)

10. JSAT Diving • Expedition Centres • Ascension (currently suspended due to runway) • Cyprus • Gibraltar • Plymouth • Others (Balmacarra, Porthkerris, Castlemartin) • MoD Approved Centres • COM-MACVarious civilian dive centres checked annually and approved for Service diving • MIL-MAC Military L4 JSAT Diving Centres • Branches and Unit Expeditions • Military or Civilian Dive Branch individual expeditions • BSAC Regional or Mil SAC Associations

11. Module OT4 Ocean Diver Dive planning & Nitrox

12. Module content • The practicalities of dive planning • Decompression planning • Dive instruments • Differences between tables and computers • Altitude and diving • Flying and diving • Oxygen toxicity limits • Gas consumption planning • Breathing gas mixes (Nitrox)

13. Decompression planning • DCI avoidance • Nitrogen management • Plan dive depth and duration • Use dive tables or computer • Using nitrox • Less nitrogen means reduced risk of DCI • Ocean Divers may use nitrox mixes up to 36% • Dive tables • Understanding the principles of BSAC tables will help you understand dive computers

14. Deepest depth Dive time 6m 6m Dive tables – definitions • Depth • Deepest depth reached during the dive in metres • Descent rate • Maximum is 30m/minute • Ascent rate • Maximum is 15m/minute up to 6m • Take one minute from 6m to the surface • Ascent check depth • At 6m pause to check dive time and depth • Dive time • From leaving surface, to arriving at 6m

15. CTC SC Dive tables – tissue codes • Current tissue code (CTC) • Represents your current nitrogen saturation • Starting point for dive planning • Surfacing code (SC) • Represents your nitrogen saturation at end of dive • On the surface after a dive • Continued ‘off-gassing’ reduces tissue nitrogen loading • Surface interval reduces CTC • Gives new CTC for a second dive • Tissue Codes : A B C D E F G Nitrogen Load

16. Dive tables – single dive planning • Ocean Divers • Maximum depth 20 metres • No-stop dives for minimum risk – use the white zone • Dive up to nitrox 36% , plan on air tables for minimum risk • Table A for divers with a CTC of A • Example • Dive to 9m for 17 min. • Surfacing code is B • If time or depth between values use next longer time/next deeper depth

17. Quiz 1 • What is dive time? • Time from leaving the surface, to arriving at 6m • What is your surfacing code after your first dive of the day to 20m for 30 minutes? • E • What is your surfacing code after a first dive to 12m for 40 minutes? • D

18. Dive tables – surface interval • Surface interval table • To find your CTC for a second dive • Enter at your SC • Move across to your surface interval • Read new CTC from table • Example • SC = E • Surface interval = 5 hours • New CTC = B • Use table B for planning

19. Dive tables – repeat dive planning • Plan second dive shallower than first • Select table that matches your CTC • Select depth • Read off dive time • Example • CTC = C = Table C • Want to dive to 15m • Max dive time is 24 min • Surface code will be F

20. Dive instruments • To dive the plan made using tables you need • Depth gauge • Watch • Dive slate • Gas analyser (nitrox mixes) • Plan the dive and dive the plan

21. Dive computers • Computer functions • Calculate nitrogen loading • Provide planning information (depth and time) • Allow personal risk settings • Record depth, time and temperature • Give audible and screen warnings • Log previous dives

22. Dive computers – dive planning • Single dive planning • Read instruction manual • Switch on and select planning mode • Set planned depth and look up no-stop time • ‘Little longer’ or ‘little deeper’ • Use a slate to record the plan • Repeat dive planning • Computer knows surface interval • Repeat as single dive planning • Computers are linked to a single diver • Plan the dive and dive the plan PRESS PRESS PRESS PRESS

23. Tables versus computers • Different dive profiles • Dive tables: ‘square’ profile based on maximum depth • Dive computers: variable or multi-level profile • Dive computers: more data in real time

24. Dive plans • Whether using tables or computers • Do the deepest dive first • Never push the limits of tables or computers • Start deep and progress to the shallows • BSAC tables allow for 3 dives in 24 hours • Computers may have similar limits • Buddies may have different profiles • Adhere to the most conservative profile

25. Limitations of tables and computers • Tables and computers • Both minimise risk of DCI but not infallible • DCI risk factors • Cold • Alcohol/drugs • Poor buoyancy control • ‘Saw-tooth’ profiles • Individual susceptibility • Fitness • Exertion • Dehydration • Pre-dispositions

26. Altitude and diving • Table levels • Level 1 tables for sea level • Levels 2, 3 and 4 for altitude • Require additional training • When to use other levels • Travelling - hills and mountains • Living or diving at altitude • Inland sites in bad weather • Flying • Computers and altitude • Read instruction manual

27. Flying and diving • Flying before diving • Tissues off-gas • Stresses of flying • Recover before diving - 10 hours minimum • Flying after diving • Increased level of off-gassing – DCI • Stresses of flying • Ensure long surface interval between last dive and flying • Tables require CTC of A or B • Computers – follow instructions

28. Oxygen toxicity • Nitrox • Reduces DCI risk but increases oxygen toxicity risk • Ocean Diver should not exceed 20m • Dive computer settings • Set to air to reduce DCI risk • Using nitrox setting increases dive time and increases DCI risk

29. Gas consumption planning • Gas planning • Ensure sufficient gas for the dive • Ensure good reserve • Rule of thirds • Use one-third out • Use one-third return • Keep one-third in reserve

30. Rule of thirds • Example: • Cylinder start pressure • 210 bar • Cylinder pressure at turn around / half way point • 140 bar • Cylinder pressure at surface • 70 bar as reserve • Always aim to surface with 1/3 of your gas in reserve • 50 bar should an absolute minimum reserve

31. Gas monitoring • Regularly monitor your contents gauge – it is your lifeline • Running low or out of gas should not arise under normal diving conditions • Gas consumption increases when • Physical effort increases • Divers are cold or anxious • Shorten or terminate the dive

32. Quiz 2 • How deep can an Ocean Diver go on 32% nitrox? • 20m • How much gas should be held in reserve? • 1/3 but not less than 50 bar • What are the risk factors for DCI? • Poor buoyancy control • Cold • Dehydration • Alcohol/drug consumption

33. Using nitrox • What is nitrox? • A breathing gas with >22% oxygen • Nitrox mix defined by the Oxygen content • Nitrox 32 – 32% oxygen + 68% nitrogen • Nitrox 36 – 36% oxygen + 64% nitrogen

34. Nitrox benefits • Advantages of less nitrogen • Reduced risk of DCI when used with air table or computer • Some divers find it reduces fatigue • Disadvantages • Nitrox divers can still suffer DCI • Some methods of cylinder filling can expose cylinders to 100% oxygen • Cylinders need periodic cleaning • Oxygen toxicity

35. Oxygen toxicity • Risk increases with • Depth • Dive duration • Percentage of oxygen • Avoidance • Observe maximum operating depth (MOD) • Signs and symptoms • Sight or hearing disturbance • Muscular twitching • Convulsions • Unconsciousness • Treatment • Abort the dive and return to surface Depth MOD Dive duration

36. Avoiding oxygen toxicity • Guidance for Ocean Divers • Only allowed to dive to a maximum depth of 20 metres • Participate only in no-stop dives using air or nitrox up to 36% • Adherence to these guidelines make oxygen toxicity very unlikely • Plan dives using an air table or air computer

37. Nitrox analysers • Nitrox must be checked with an oxygen analyser before use • Mix should not vary more than ±1% from the desired mix • All cylinders should be clearly marked with oxygen percentage and MOD • MOD = maximum safe depth for the nitrox mix • Follow analyser manufacturer’s guidance

38. Analysing a nitrox mix • Ideally check the mix yourself • Calibrate the analyser • Keep flow rate even and low • Avoid windy conditions • Avoid moisture • Store analyser away from elevated oxygen levels • If using a filling station • Ask the technician to analyse the gas in your presence • Filling stations may require a signature to confirm the percentage supplied • Present your nitrox qualification when ordering a mix 1. Switch on 2. Calibrate 3. Open cylinder 4. Analyse 5. Take reading

39. Quiz 2 • What are the signs and symptoms of oxygen toxicity? • Sight or hearing disturbances • Muscular twitching • Convulsions • Unconsciousness • What are the advantages of nitrox? • Reduced risk of DCI when used with air table or computer

40. Rebreather Divers • Rebreathers • What are Rebreathers • Buddy considerations when diving with Rebreather divers

41. Mouthpiece Counter-lungs Gas Cylinder Absorbent canister (the scrubber) What is a Rebreather A continuous breathing loop • Divers lungs and mouthpiece • Breathing bags (counter-lungs) • Recycles gas through ‘ loop’ using one way valves to maintain gas flow • Carbon dioxide (CO2) removal - absorbent or ‘scrubber’ canister • Requires small gas supply connected into loop to replenish oxygen consumed by respiration Delivers nitrox mixes

42. Types of Rebreather Semi-closed Circuit Rebreather (SCR) • Cylinder of pre-selected gas mix • Maximum operating depth (MOD) determined by mix being used • Excess gas vented off periodically, bubbles Closed Circuit Rebreather (CCR) • 2 cylinders, oxygen and air • Electronically controlled - optimum Nitrox mix to depth • No bubbles, except for venting on ascent Both systems should have an adequate bailout system that can be used as an AS

43. Diving with Rebreathers • Diving on Rebreathers requires additional training and practice • Advantages • Extends dive duration by the gas recycling process • Extends no-stop dive times appropriate to gas mixed being breathed • No or hardly any bubbles - get much closer to marine life • Disadvantages • Rigorous monitoring • Rigorous maintenance and preparation

44. Diving with Rebreather Divers • If a Sport Diver buddies a Rebreather diver • Dive is planned to • The most conservative decompression schedule of the gases being used • The most conservative operating MOD determined by either of the gases used • Must be experienced in the type of diving conditions for the dive • Must be able to recognise underwater problems pertinent to Rebreather diver • Must be able to perform CBL and surface support on Rebreather diver • Rebreather Try Dive, Practice

45. Questions • ?

46. Module OT4 • BSAC as an Organisation • BSAC Diver progression • JSAT Diving • Decompression planning • Oxygen toxicity limits • Gas consumption planning • Breathing gas mixes • Diving with Rebreathers  Summary