BSAC OCEAN DIVER STUDY GUIDE
Elected commitee - Answers :Diving officer
Training officer
Chairperson
Treasurer
Secretary
Equipment officer
Branches vs BSAC centres - Answers :Branches = local club (around 1000 branches
around UK and overseas), BSAC centre are training centres i.e. professional diving
schools
BSAC organisation structure - Answers :BSAC President, BSAC Council, National
Diving Committee, Regional Coaching Team - BSAC council made up of elected
members who manage BSAC for members - NDC members appointed for expertise - all
unpaid volunteers
Ocean diver aim - Answers :Dive in open water to 20m under supervision of a dive
manager in controlled conditions.
Discovery diver aim - Answers :12m depth under direct in water supervision of a dive
leader
BSAC council - Answers :committee that manages bsac on behalf of the members
Atmospheric pressure - Answers :Weight of 1 cm square column of air is 1 kg at sea
level - - i.e. 1 bar at sea level
Water pressure - Answers :Water column with area of 1cm2 exerts downwards pressure
of 1 bar for every 10 metres
How to measure water pressure - Answers :Depth gauges, gives reading in metres
10m water pressure and total pressure is - Answers :1 bar water pressure and 1 bar
atmospheric pressure = 2 bar total pressure
20m water pressure and total pressure is - Answers :2 bar water pressure and 1 bar
atmospheric pressure = 3 bar total pressure
Effect of pressure on air spaces - Answers :2 bar, volume of air is halved. 3 bar reduces
to 1 third original volume. 4 bar reduces to one quarter original volume
Body water content - Answers :80 per cent
,Mask - Answers :Rigid mask frame
Tempered glass
Flexible seal of silicone rubber
Wash your mask in fresh water after each dive - avoid drying in direct sun as can affect
flexibility of silicone rubber
Fins - Answers :Either shoe fin with foot pocket (in warm conditions) or strap fin (over
boots, with strap or spring to keep in place) - wash in fresh water and dry standing on
food pocket end
SCUBA acronym - Answers :self contained underwater breathing apparatus
Scuba equipment - Answers :Cylinder
Buoyancy Compensator
Regulator
Cylinder working pressures - Answers :232/300 bar
Cylinder material - Answers :Aluminium/steel
Must conform to PRESSURE EQUIPMENT DIRECTIVE (bears the CE mark)
Type of gas it contains will be written on it
SCUBA cylinder testing - Answers :Visual check every 2.5 years
Hydrostatic test every 5 years
Cylinder care - Answers :Wash in fresh water
Store cylinder upright
Nitrox 32 mix/Nitrogen 36 mix/air - Answers :32 - 32% oxygen and 68% nitrogen
36 - 36% O and 64% N
Air - 21% O and 79% N
Marking - WC - Answers :how many litres of water the cylinder could hold
WP or CP - Answers :Working pressure - 232 bar or 300 bar
TP - Answers :Test pressure - used during hydraulic test
CP - Answers :Charging pressure
Nitrox cylinders - Answers :Need to be in Oxygen service - oxygen compatible parts in
valves and need periodic cleaning to ensure no hydrocarbons present (recommended
every 15 months)
A clamp - Answers :Makes use of an O ring set into the valve outlet
232 bar pressure
, DIN - Answers :No o ring
Fitted to cylinders up to 300 bar
Can add on a clamp equipment to allow use of regulators equipped with A-clamp
attachment
Not all DIN support all pressure types
M26 - Answers :USed above 22% oxygen
BCD components - Answers :Integrated gas bladder filled by direct feed which connects
via an Intermediate pressure hose to the regulator - push button to inflate BC
Oral inflation mouth piece
Over inflation pressure relief valves
Also has manually operated dump mechanism
-Washed inside and out with fresh water - disinfecting solutions should be used inside
BCD - should be dry and stored slightly inflated - do not breathe from BC
Regulators - Answers :Deliver air at ambient pressure - first stage reduces pressure in
cylinder to intermediate pressure around 10 bar above ambient - gas passed down
interstage, intermediate pressure hose to regulator second stage-second stage reduces
pressure further to ambient pressure - exhaled air expelled via exhaust valve - contain a
octopus for your buddy/you
-Alternative source is additional second stage regulator connected to first stage - back
up system for diver or buddy - usually marked yellow and stamped with A
-Contents gauge connected via hose to first stage - has to be high pressure hose as it
delivers high pressure gas for gauge to read
-Many designed for use in temperatures above 10 degrees - regulators with Nitrox
should be in Oxygen service
Regulator care - Answers :Wash while pressurized and connected to cylinder, do not
press purge button while washing with fresh water -dry before storing
Serviced once a year
Weights - Answers :Usually on belt with quick release buckle - or can be in harness -
some BCs had integrated weight pockets - require mechanism for easy jettisoning - but
important weight not lost unintentionally - release mechanisms can be buckle, velcro or
release clips
-Washed in fresh water and allowed to dry before storage
What must never be done - Answers :Holding breath - as pressure decreases on ascent
air in lungs at ambient pressure would increase in volume, causing damage
Elected commitee - Answers :Diving officer
Training officer
Chairperson
Treasurer
Secretary
Equipment officer
Branches vs BSAC centres - Answers :Branches = local club (around 1000 branches
around UK and overseas), BSAC centre are training centres i.e. professional diving
schools
BSAC organisation structure - Answers :BSAC President, BSAC Council, National
Diving Committee, Regional Coaching Team - BSAC council made up of elected
members who manage BSAC for members - NDC members appointed for expertise - all
unpaid volunteers
Ocean diver aim - Answers :Dive in open water to 20m under supervision of a dive
manager in controlled conditions.
Discovery diver aim - Answers :12m depth under direct in water supervision of a dive
leader
BSAC council - Answers :committee that manages bsac on behalf of the members
Atmospheric pressure - Answers :Weight of 1 cm square column of air is 1 kg at sea
level - - i.e. 1 bar at sea level
Water pressure - Answers :Water column with area of 1cm2 exerts downwards pressure
of 1 bar for every 10 metres
How to measure water pressure - Answers :Depth gauges, gives reading in metres
10m water pressure and total pressure is - Answers :1 bar water pressure and 1 bar
atmospheric pressure = 2 bar total pressure
20m water pressure and total pressure is - Answers :2 bar water pressure and 1 bar
atmospheric pressure = 3 bar total pressure
Effect of pressure on air spaces - Answers :2 bar, volume of air is halved. 3 bar reduces
to 1 third original volume. 4 bar reduces to one quarter original volume
Body water content - Answers :80 per cent
,Mask - Answers :Rigid mask frame
Tempered glass
Flexible seal of silicone rubber
Wash your mask in fresh water after each dive - avoid drying in direct sun as can affect
flexibility of silicone rubber
Fins - Answers :Either shoe fin with foot pocket (in warm conditions) or strap fin (over
boots, with strap or spring to keep in place) - wash in fresh water and dry standing on
food pocket end
SCUBA acronym - Answers :self contained underwater breathing apparatus
Scuba equipment - Answers :Cylinder
Buoyancy Compensator
Regulator
Cylinder working pressures - Answers :232/300 bar
Cylinder material - Answers :Aluminium/steel
Must conform to PRESSURE EQUIPMENT DIRECTIVE (bears the CE mark)
Type of gas it contains will be written on it
SCUBA cylinder testing - Answers :Visual check every 2.5 years
Hydrostatic test every 5 years
Cylinder care - Answers :Wash in fresh water
Store cylinder upright
Nitrox 32 mix/Nitrogen 36 mix/air - Answers :32 - 32% oxygen and 68% nitrogen
36 - 36% O and 64% N
Air - 21% O and 79% N
Marking - WC - Answers :how many litres of water the cylinder could hold
WP or CP - Answers :Working pressure - 232 bar or 300 bar
TP - Answers :Test pressure - used during hydraulic test
CP - Answers :Charging pressure
Nitrox cylinders - Answers :Need to be in Oxygen service - oxygen compatible parts in
valves and need periodic cleaning to ensure no hydrocarbons present (recommended
every 15 months)
A clamp - Answers :Makes use of an O ring set into the valve outlet
232 bar pressure
, DIN - Answers :No o ring
Fitted to cylinders up to 300 bar
Can add on a clamp equipment to allow use of regulators equipped with A-clamp
attachment
Not all DIN support all pressure types
M26 - Answers :USed above 22% oxygen
BCD components - Answers :Integrated gas bladder filled by direct feed which connects
via an Intermediate pressure hose to the regulator - push button to inflate BC
Oral inflation mouth piece
Over inflation pressure relief valves
Also has manually operated dump mechanism
-Washed inside and out with fresh water - disinfecting solutions should be used inside
BCD - should be dry and stored slightly inflated - do not breathe from BC
Regulators - Answers :Deliver air at ambient pressure - first stage reduces pressure in
cylinder to intermediate pressure around 10 bar above ambient - gas passed down
interstage, intermediate pressure hose to regulator second stage-second stage reduces
pressure further to ambient pressure - exhaled air expelled via exhaust valve - contain a
octopus for your buddy/you
-Alternative source is additional second stage regulator connected to first stage - back
up system for diver or buddy - usually marked yellow and stamped with A
-Contents gauge connected via hose to first stage - has to be high pressure hose as it
delivers high pressure gas for gauge to read
-Many designed for use in temperatures above 10 degrees - regulators with Nitrox
should be in Oxygen service
Regulator care - Answers :Wash while pressurized and connected to cylinder, do not
press purge button while washing with fresh water -dry before storing
Serviced once a year
Weights - Answers :Usually on belt with quick release buckle - or can be in harness -
some BCs had integrated weight pockets - require mechanism for easy jettisoning - but
important weight not lost unintentionally - release mechanisms can be buckle, velcro or
release clips
-Washed in fresh water and allowed to dry before storage
What must never be done - Answers :Holding breath - as pressure decreases on ascent
air in lungs at ambient pressure would increase in volume, causing damage
