BSAC OCEAN DIVER QUESTIONS &
ANSWERS(GRADED A+)
Elected commitee - ANSWERDiving officer
Training officer
Chairperson
Treasurer
Secretary
Equipment officer
Branches vs BSAC centres - ANSWERBranches = local club (around 1000 branches
around UK and overseas), BSAC centre are training centres i.e. professional diving
schools
BSAC organisation structure - ANSWERBSAC 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 - ANSWERDive in open water to 20m under supervision of a dive
manager in controlled conditions.
Discovery diver aim - ANSWER12m depth under direct in water supervision of a dive
leader
BSAC council - ANSWERcommittee that manages bsac on behalf of the members
Atmospheric pressure - ANSWERWeight of 1 cm square column of air is 1 kg at sea
level - - i.e. 1 bar at sea level
Water pressure - ANSWERWater column with area of 1cm2 exerts downwards pressure
of 1 bar for every 10 metres
How to measure water pressure - ANSWERDepth gauges, gives reading in metres
10m water pressure and total pressure is - ANSWER1 bar water pressure and 1 bar
atmospheric pressure = 2 bar total pressure
20m water pressure and total pressure is - ANSWER2 bar water pressure and 1 bar
atmospheric pressure = 3 bar total pressure
Effect of pressure on air spaces - ANSWER2 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 - ANSWER80 per cent
Mask - ANSWERRigid 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 - ANSWEREither 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 - ANSWERself contained underwater breathing apparatus
Scuba equipment - ANSWERCylinder
Buoyancy Compensator
Regulator
Cylinder working pressures - ANSWER232/300 bar
Cylinder material - ANSWERAluminium/steel
Must conform to PRESSURE EQUIPMENT DIRECTIVE (bears the CE mark)
Type of gas it contains will be written on it
SCUBA cylinder testing - ANSWERVisual check every 2.5 years
Hydrostatic test every 5 years
Cylinder care - ANSWERWash in fresh water
Store cylinder upright
Nitrox 32 mix/Nitrogen 36 mix/air - ANSWER32 - 32% oxygen and 68% nitrogen
36 - 36% O and 64% N
Air - 21% O and 79% N
Marking - WC - ANSWERhow many litres of water the cylinder could hold
WP or CP - ANSWERWorking pressure - 232 bar or 300 bar
TP - ANSWERTest pressure - used during hydraulic test
CP - ANSWERCharging pressure
How to dive with table - ANSWERNeed depth guage (to monitor depth), diving watch (to
monitor time) and diving slate (to write down plan)
, Decompression procedures - ANSWER-Last 10m is where there is greatest ambient
pressure change
-BSAC tables specify maximum ascent rate of 15 metres a minute up to six metres -
ascent from six metres to surface should take one minutes
-Divers need to slow ascent before the check depth of 6m to ensure they have absolute
buoyancy control at six metres
No-stop diving - ANSWEROcean divers carry out no-stop diving to a maximum depth of
20m - this is to introduce minimum risk - longer or deeper dives cause more nitrogen to
be absorbed, may not be safely eliminated upon direct ascent - these dives require
decompression stops - diver will maintain accurate control of their buoyancy and stop at
various points during ascent to allow greater nitrogen release
Nitrox cylinders - ANSWERNeed 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 - ANSWERMakes use of an O ring set into the valve outlet
232 bar pressure
DIN - ANSWERNo 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 - ANSWERUSed above 22% oxygen
BCD components - ANSWERIntegrated 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 - ANSWERDeliver 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
ANSWERS(GRADED A+)
Elected commitee - ANSWERDiving officer
Training officer
Chairperson
Treasurer
Secretary
Equipment officer
Branches vs BSAC centres - ANSWERBranches = local club (around 1000 branches
around UK and overseas), BSAC centre are training centres i.e. professional diving
schools
BSAC organisation structure - ANSWERBSAC 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 - ANSWERDive in open water to 20m under supervision of a dive
manager in controlled conditions.
Discovery diver aim - ANSWER12m depth under direct in water supervision of a dive
leader
BSAC council - ANSWERcommittee that manages bsac on behalf of the members
Atmospheric pressure - ANSWERWeight of 1 cm square column of air is 1 kg at sea
level - - i.e. 1 bar at sea level
Water pressure - ANSWERWater column with area of 1cm2 exerts downwards pressure
of 1 bar for every 10 metres
How to measure water pressure - ANSWERDepth gauges, gives reading in metres
10m water pressure and total pressure is - ANSWER1 bar water pressure and 1 bar
atmospheric pressure = 2 bar total pressure
20m water pressure and total pressure is - ANSWER2 bar water pressure and 1 bar
atmospheric pressure = 3 bar total pressure
Effect of pressure on air spaces - ANSWER2 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 - ANSWER80 per cent
Mask - ANSWERRigid 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 - ANSWEREither 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 - ANSWERself contained underwater breathing apparatus
Scuba equipment - ANSWERCylinder
Buoyancy Compensator
Regulator
Cylinder working pressures - ANSWER232/300 bar
Cylinder material - ANSWERAluminium/steel
Must conform to PRESSURE EQUIPMENT DIRECTIVE (bears the CE mark)
Type of gas it contains will be written on it
SCUBA cylinder testing - ANSWERVisual check every 2.5 years
Hydrostatic test every 5 years
Cylinder care - ANSWERWash in fresh water
Store cylinder upright
Nitrox 32 mix/Nitrogen 36 mix/air - ANSWER32 - 32% oxygen and 68% nitrogen
36 - 36% O and 64% N
Air - 21% O and 79% N
Marking - WC - ANSWERhow many litres of water the cylinder could hold
WP or CP - ANSWERWorking pressure - 232 bar or 300 bar
TP - ANSWERTest pressure - used during hydraulic test
CP - ANSWERCharging pressure
How to dive with table - ANSWERNeed depth guage (to monitor depth), diving watch (to
monitor time) and diving slate (to write down plan)
, Decompression procedures - ANSWER-Last 10m is where there is greatest ambient
pressure change
-BSAC tables specify maximum ascent rate of 15 metres a minute up to six metres -
ascent from six metres to surface should take one minutes
-Divers need to slow ascent before the check depth of 6m to ensure they have absolute
buoyancy control at six metres
No-stop diving - ANSWEROcean divers carry out no-stop diving to a maximum depth of
20m - this is to introduce minimum risk - longer or deeper dives cause more nitrogen to
be absorbed, may not be safely eliminated upon direct ascent - these dives require
decompression stops - diver will maintain accurate control of their buoyancy and stop at
various points during ascent to allow greater nitrogen release
Nitrox cylinders - ANSWERNeed 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 - ANSWERMakes use of an O ring set into the valve outlet
232 bar pressure
DIN - ANSWERNo 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 - ANSWERUSed above 22% oxygen
BCD components - ANSWERIntegrated 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 - ANSWERDeliver 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
