Sports Diver Knowledge: ST5 - Breathing, gas planning and systems

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* 1. If you begin your dive with 210 bar of gas in your cylinder, what is the minimum amount of gas (in bar) you should plan to have left on reaching the surface at the end of your dive?

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* 2. Which surface breathing rate should you use when calculating the amount of gas required for a dive?

25 litres per minute

your actual surface breathing rate

your actual surface breathing rate or 25 litres per minute, whichever is the higher

your actual surface breathing rate or 25 litres per minute, whichever is the lower

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* 3. Which of the following can increase breathing rates?

Physical size

Fitness level

Energy output

Body temperature

Nervousness

All of the above

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* 4. Your surface breathing rate is 20 litres per minute. How much breathing gas (in litres) is required for a dive to 30 metres for 20 minutes?

1600

2000

2400

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* 5. You plan to dive to 28 metres for 22 minutes with a surface breathing rate of 25 litres per minute. You have a choice of 10L, 12L, 12.5L, and 15L cylinders each filled to 220 bar. Which is the smallest cylinder that contains enough gas for the dive?

10L

12L

12.5L

15L

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* 6. What breathing rate (expressed as litres per minute at the surface) are you advised to expect during the initial phases of an emergency?

Your normal breathing rate

double your normal breathing rate

25 litres per minute

50 litres per minute

100 litres per minute

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* 7. How long (in minutes) would the gas in a 3L cylinder filled to 200 bar last in an emergency at 30 metres if the user's breathing rate (surface) was 50 litres per minute?

3 mins

3 mins 20 seconds

3 mins 40 seconds

3 mins 50 seconds

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* 8. Which of the following AS configurations protects the wearer completely against 1st stage failure? Please select all that apply.

Octopus

BC demand valve

2 independent regulators/single cylinder

manifolded twin cylinders

manifolded twin cylinders with isolation valve

independent twin cylinders

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* 9. Which of the following AS configurations leaves both divers breathing from the same cylinder when it's in use? Please select all that apply.

Octopus

BC demand valve

2 independent regulators/single cylinder

single cylinder plus pony

independent twin cylinders

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* 10. What sort of regulator second stage is suitable for use as an octopus?

An old but still functioning one

A new budget model

A high performance model

One of similar performance to the primary second stage

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* 11. What sort of first stage is required for use with an octopus system?

Any regulator provided it is in good condition

A new one

A high performance one

An environmentally sealed one