Sports Diver Knowledge Quiz

ST4 - Deeper Diving

The partial pressure of nitrogen in a breath taken during a dive on air is 2.37 bar. What is the depth? See Student Workbook p56
1. 10.0 m
2. 12.37 m
3. 20.0 m
4. 23.7 m
5. It is not possible to determine the depth from the information given
What is the upper limit of partial pressure of oxygen for BSAC divers (without additional technical qualifications)? See Student Workbook p58
1. No limit: oxygen is beneficial to divers
2. 21%
3. 40%
4. 1.0 bar
5. 1.4 bar
6. 1.6 bar
Use the BSAC Nitrox Tables to determine the partial pressure of oxygen at a depth of 25 metres for nitrox 25%. See Student Workbook pp57-58
1. 0.85
2. 0.875
3. 0.93
4. 1.00
5. 1.40
Calculate the partial pressure of oxygen at a depth of 25 metres for nitrox 25%. Do not use tables. See Student Workbook p57
1. 0.85
2. 0.875
3. 0.93
4. 1.00
5. 1.40
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? See Student Workbook pp58-59
1. air
2. nitrox 30%
3. nitrox 31%
4. nitrox 32%
5. nitrox 33%
6. nitrox 34%
7. nitrox 35%
8. nitrox 36%
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? See Student Workbook p59 and p62
1. Jane
2. Dave
3. Both Dave and Jane
4. Neither of them
Which of the following are effects of nitrogen narcosis? See Student Workbook pp60-62
1. Quick response to buddy signals
2. Making errors when reading gauges and making choices
3. Being very alert
4. Sticking to the agreed dive plan
5. Feeling confident
6. Continually monitoring your buddy for narcosis signs
7. Feeling dizzy, seeing stars, hallucinations
8. Task fixation
Which of the following factors might contribute to nitrogen narcosis, or make it worse. Tick all that are relevant. See Student Workbook pp60-62
1. Depths less than 20m
2. Depths over 30m
3. Using nitrox 32% instead of air
4. Hard work underwater
5. Darkness
6. Cold
7. Prior consumption of alcohol
8. Wearing a comfortable new drysuit
9. Using nitrox 36% instead of nitrox 32%
Which one of the following factors MUST be present for the effects of nitrogen narcosis to be noticed? See Student Workbook pp60-62
1. Depths less than 10m
2. Depths of about 30m or more
3. Using nitrox 32% instead of air
4. Hard work underwater
5. Darkness
6. Cold
7. Prior consumption of alcohol
8. Wearing a comfortable new drysuit
9. Using nitrox 36% instead of nitrox 32%
Which of the following are recommended ways to deal with the effects of nitrogen narcosis? See Student Workbook p62
1. Rapid descent
2. Physical fitness
3. Mental fitness
4. Ascend to a shallower depth
5. Avoid task fixation
6. Progressive build-up of depth experience
7. Monitor your buddy closely
What depth does BSAC recommend as the absolute limit for air diving? See Student Workbook p61
1. 20 metres
2. 35 metres
3. 40 metres
4. 50 metres
5. 60 metres
CNS toxicity can be caused by ______. See Student Workbook p64
1. Using air as a breathing gas in preference to nitrox
2. Breathing high partial pressures of nitrogen
3. Breathing high partial pressures of oxygen
4. Missed decompression stops
5. A neck seal that is too tight
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? See Student Workbook p66
1. 44.88%
2. 22.44%
3. 11.22%
4. 5.61%
What is the dive time in the dive shown in the profile below? See Student Workbook p67
1. 22 minutes
2. 25 minutes
3. 28 minutes
4. 29 minutes
If the dive shown in the profile below 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? See Student Workbook p67 and BSAC 88 or Nitrox Tables
1. A decompression stop at 9 metres
2. A safety stop at 9 metres
3. A decompression stop at 6 metres
4. A safety stop at 6 metres
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)? See Student Workbook p73
1. Yes: you don't need it so it's not a problem for your buddy to use it
2. Yes: because he has done broadly similar dives to you, though his were for a longer duration, it will be OK to use it
3. Yes: because all the diving has been in 15m or less
4. No: he might not understand the display
5. No: your computer has not got his previous dives logged and might underestimate his decompression requirements
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 _______ See Student Workbook p77
1. They were not a specialist firm organising diving holidays
2. Divers' knives (shown in the advert) are a security risk and are not allowed
3. Diving before flying means that it would not be possible to drink alcohol on the return flight
4. Any period spent at reduced pressure or altitude immediately after a dive will put the diver at greater risk of DCI