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

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

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. 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
Sports Diver
Dive Leader
Advanced Diver
First Class
(Regional preparation courses and exams)
Skill Development Courses (SDCs)…

7. Further Branch Training (SDC’s)
Branch Diving
Dive UK
Wreck Appreciation
Wreck Diver
Dive Planning & Management
Search & Recovery
Buoyancy & Trim
Drysuit
Compressor Operator
Diving For All
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)
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. (National Governing Body)
BSAC Diving Grades
Military
BRd 2806(5)
British Sub Aqua Club
(National Governing Body)
Ocean Diver
(4 dives)
Sports Diver
(10-20 dives)
Dive Leader
(50+ dives)
Advanced Diver
(150+ dives)
First Class Diver
Open Water Instr
Advanced Instr
National Instr
Instructor
Foundation Cse
Instructor Trainer
Branch SADS
Expedition SADS

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-MAC Various 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. 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 6m
Deepest depth
Dive time 6m

15. Dive tables – tissue codes
CTC SC
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
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
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
1. Switch on
Analysing a nitrox mix
2. Calibrate
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
4. Analyse
3. Open cylinder
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. What is a Rebreather A continuous breathing loop
Mouthpiece
Divers lungs and mouthpiece
Counter-lungs
Breathing bags (counter-lungs)
Recycles gas through ‘ loop’ using one way valves to maintain gas flow
Gas Cylinder
Carbon dioxide (CO2) removal - absorbent or ‘scrubber’ canister
Requires small gas supply connected into loop to replenish oxygen consumed by respiration
Absorbent canister (the scrubber)
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. Summary BSAC as an Organisation BSAC Diver progression JSAT Diving
Module OT4
Summary
BSAC as an Organisation
BSAC Diver progression
JSAT Diving
Decompression planning
Oxygen toxicity limits
Gas consumption planning
Breathing gas mixes
Diving with Rebreathers