Sports Diver Knowledge: ST4 - Deeper Diving

Question Title

* 1. The partial pressure of nitrogen in a breath taken during a dive on air is 2.37 bar. What is the depth?

10.0 m

12.37 m

20.0 m

23.7 m

It is not possible to determine the depth from the information given

Question Title

* 2. What is the upper limit of partial pressure of oxygen for BSAC divers (without additional technical qualifications)?

No limit: oxygen is beneficial to divers

21%

40%

1.0 bar

1.4 bar

1.6 bar

Question Title

* 3. Use the BSAC Nitrox Tables to determine the partial pressure of oxygen at a depth of 27 metres for nitrox 25%.

0.85

0.875

0.93

1.00

1.40

Question Title

* 4. Calculate the partial pressure of oxygen at a depth of 25 metres for nitrox 25%. Do not use tables.

0.85

0.875

0.93

1.00

1.40

Question Title

* 5. You are going to dive an intact upright wreck which lies in 32 metres, with its highest point at 18m. What mix will allow you the longest safe dive time while visiting the whole of the wreck including the propellers and rudder?

air

nitrox 30%

nitrox 31%

nitrox 32%

nitrox 33%

nitrox 34%

nitrox 35%

nitrox 36%

Question Title

* 6. You overhear two divers discussing nitrogen on and off gassing. Jane says slow tissues, those with poorer blood supply such as the brain and heart, will on or off gas more slowly. Dave says that off gassing stops once a diver reaches the surface because the partial pressure of nitrogen in the body is then equal to that in the air. Who is correct?

Jane

Dave

Both Dave and Jane

Neither of them

Question Title

* 7. Which of the following are effects of nitrogen narcosis? Please select all that apply.

Quick response to buddy signals

Making errors when reading gauges and making choices

Being very alert

Sticking to the agreed dive plan

Feeling over-confident

Continually monitoring your buddy for narcosis signs

Feeling dizzy, seeing stars, hallucinations

Task fixation

Question Title

* 8. Which of the following factors might contribute to nitrogen narcosis, or make it worse? Please select all that apply.

Depths less than 20m

Depths over 30m

Using nitrox 32% instead of air

Hard work underwater

Darkness

Cold

Prior consumption of alcohol

Wearing a comfortable new drysuit

Using nitrox 36% instead of nitrox 32%

Question Title

* 9. Which one of the following factors MUST be present for the effects of nitrogen narcosis to be noticed?

Depths less than 10m

Depths of about 30m or more

Using nitrox 32% instead of air

Hard work underwater

Darkness

Cold

Prior consumption of alcohol

Wearing a comfortable new drysuit

Using nitrox 36% instead of nitrox 32%

Question Title

* 10. Which of the following are recommended ways to deal with the effects of nitrogen narcosis? Please select all that apply.

Rapid descent

Physical fitness

Mental fitness

Ascend to a shallower depth

Avoid task fixation

Progressive build-up of depth experience

Monitor your buddy closely

Question Title

* 11. What depth does BSAC recommend as the absolute limit for air diving?

20 metres

35 metres

40 metres

50 metres

60 metres

Question Title

* 12. CNS toxicity can be caused by ______?

Using air as a breathing gas in preference to nitrox

Breathing high partial pressures of nitrogen

Breathing high partial pressures of oxygen

Missed decompression stops

A neck seal that is too tight

Question Title

* 13. If your CNS% after your first dive was 22.44% what should you consider it to be at the start of your next dive 3 hours later?

44.88%

22.44%

11.22%

5.61%

Question Title

* 14. What is the dive time in the dive shown in the profile below?

22 minutes

25 minutes

28 minutes

29 minutes

Question Title

* 15.
If the dive shown in the profile above was using air as the breathing gas at sea level with atmospheric pressure 1000 millibars, and was preceded by no diving for at least 16 hours, what was happening between 25 and 28 minutes?

A decompression stop at 9 metres

A safety stop at 9 metres

A decompression stop at 6 metres

safety stop at 6 metres

Question Title

* 16. You are on a liveaboard dive trip for a week and intend to miss the next dive. Your friend, who you have done some but not all the dives on the trip with, has a computer whose battery has failed. There is no spare, and he asks if he can borrow your computer. How should you answer (responsibly)?

Yes: you don't need it so it's not a problem for your buddy to use it

Yes: because he has done broadly similar dives to you, though his were for a longer duration, it will be OK to use it

Yes: because all the diving has been in 15m or less

No: he might not understand the display

No: your computer has not got his previous dives logged and might underestimate his decompression requirements

Question Title

* 17. A few years ago a major UK travel company ran a TV advertisement showing a diver arriving at the airport for his flight home in full diving gear. They had to withdraw the advert because _______?

They were not a specialist firm organising diving holidays

Divers' knives (shown in the advert) are a security risk and are not allowed

Diving before flying means that it would not be possible to drink alcohol on the return flight

Any period spent at reduced pressure or altitude immediately after a dive will put the diver at greater risk of DCI

Question Title

* 1. The partial pressure of nitrogen in a breath taken during a dive on air is 2.37 bar. What is the depth?

Question Title

* 2. What is the upper limit of partial pressure of oxygen for BSAC divers (without additional technical qualifications)?

Question Title

* 3. Use the BSAC Nitrox Tables to determine the partial pressure of oxygen at a depth of 27 metres for nitrox 25%.

Question Title

* 4. Calculate the partial pressure of oxygen at a depth of 25 metres for nitrox 25%. Do not use tables.

Question Title

* 5. You are going to dive an intact upright wreck which lies in 32 metres, with its highest point at 18m. What mix will allow you the longest safe dive time while visiting the whole of the wreck including the propellers and rudder?

Question Title

Question Title

* 7. Which of the following are effects of nitrogen narcosis? Please select all that apply.

Question Title

* 8. Which of the following factors might contribute to nitrogen narcosis, or make it worse? Please select all that apply.

Question Title

* 9. Which one of the following factors MUST be present for the effects of nitrogen narcosis to be noticed?

Question Title

* 10. Which of the following are recommended ways to deal with the effects of nitrogen narcosis? Please select all that apply.

Question Title

* 11. What depth does BSAC recommend as the absolute limit for air diving?

Question Title

* 12. CNS toxicity can be caused by ______?

Question Title

* 13. If your CNS% after your first dive was 22.44% what should you consider it to be at the start of your next dive 3 hours later?

Question Title

* 14. What is the dive time in the dive shown in the profile below?

Question Title

* 15. If the dive shown in the profile above was using air as the breathing gas at sea level with atmospheric pressure 1000 millibars, and was preceded by no diving for at least 16 hours, what was happening between 25 and 28 minutes?

Question Title

Question Title

* 17. A few years ago a major UK travel company ran a TV advertisement showing a diver arriving at the airport for his flight home in full diving gear. They had to withdraw the advert because _______?

* 15.
If the dive shown in the profile above was using air as the breathing gas at sea level with atmospheric pressure 1000 millibars, and was preceded by no diving for at least 16 hours, what was happening between 25 and 28 minutes?