vjongene
Contributor
I am preparing my CMAS three-star certification, and got a bunch of Q&A's to work with. Thought I would share a few of the better ones, for your instruction and entertainment.
- How can a free diver using a snorkel suffer a barotraumatism?
- Through what mechanism can a barotraumatism affect the inner ear?
- How can an eardrum rupture towards the outside?
- Why can a rapid and shallow breathing pattern develop more rapidly at depths of more than 40 m?
- During a dive at a depth of 40 m, your buddy bolts to the surface. What do you do?
- At the end of a deco dive, you and your buddy have mandatory stops at 12, 9, 6 and 3 m. Because of poor planning, you do not have enough air left to do all the stops. What do you do?
- On a dive boat, a diver complains of dizziness and numbness. He is is slightly incoherent, his skin is red, he is hot and dry to the touch. His pulse is 145/min. What is your diagnosis? What do you do?
- The engine of a dive boat loses a piece of metal, which lodges itself into the thigh of a diver below. Two thirds of the shard are stuck in the flesh. What do you do?
- A BCD with a 16 l bladder is 3/4 full at 40 m. It has an overpressure valve with a resistance of 0.2 bar. You ascend to the surface without purging. At what depth will the valve start releasing air? How many liters of air (at surface pressure) will be released from the bladder?
- You have 10 l doubles filled to 200 bar, which you use to fill three pony bottles of 0.5 l capacity. To what pressure can you fill the pony bottles, if you fill them either together on a manifold, or one after the other?
- A 10 l single has 50 bar left. It is filled from a 50 l buffer tank that holds 220 bar. After the pressures have equilibrated, the single tank has heated to 50C. What will be its pressure once cooled to 10C?
- I am diving in a mountain lake. At 20 m below the surface, my capillary depth gauge actually reads 10 m. At what altitude is the lake?
- The Dead Sea has a salt content of up to 60%. How much lead (approximately) would an 80 kg diver need to dive there?
- Air has a density of 1.26 kg/m3. Assuming that gas laws hold perfectly, what will be the apparent weight of a 1000 l bubble of air at 9000 m below the sea surface? At what depth will it be neutrally buoyant?
- You are diving on Trimix 8/71 (O2/He). At what depth will you reach a critical intoxication limit? What will be the limiting gas?
For some of these questions, the "correct" answer will depend on the training agency. Anyway, enjoy!
- How can a free diver using a snorkel suffer a barotraumatism?
- Through what mechanism can a barotraumatism affect the inner ear?
- How can an eardrum rupture towards the outside?
- Why can a rapid and shallow breathing pattern develop more rapidly at depths of more than 40 m?
- During a dive at a depth of 40 m, your buddy bolts to the surface. What do you do?
- At the end of a deco dive, you and your buddy have mandatory stops at 12, 9, 6 and 3 m. Because of poor planning, you do not have enough air left to do all the stops. What do you do?
- On a dive boat, a diver complains of dizziness and numbness. He is is slightly incoherent, his skin is red, he is hot and dry to the touch. His pulse is 145/min. What is your diagnosis? What do you do?
- The engine of a dive boat loses a piece of metal, which lodges itself into the thigh of a diver below. Two thirds of the shard are stuck in the flesh. What do you do?
- A BCD with a 16 l bladder is 3/4 full at 40 m. It has an overpressure valve with a resistance of 0.2 bar. You ascend to the surface without purging. At what depth will the valve start releasing air? How many liters of air (at surface pressure) will be released from the bladder?
- You have 10 l doubles filled to 200 bar, which you use to fill three pony bottles of 0.5 l capacity. To what pressure can you fill the pony bottles, if you fill them either together on a manifold, or one after the other?
- A 10 l single has 50 bar left. It is filled from a 50 l buffer tank that holds 220 bar. After the pressures have equilibrated, the single tank has heated to 50C. What will be its pressure once cooled to 10C?
- I am diving in a mountain lake. At 20 m below the surface, my capillary depth gauge actually reads 10 m. At what altitude is the lake?
- The Dead Sea has a salt content of up to 60%. How much lead (approximately) would an 80 kg diver need to dive there?
- Air has a density of 1.26 kg/m3. Assuming that gas laws hold perfectly, what will be the apparent weight of a 1000 l bubble of air at 9000 m below the sea surface? At what depth will it be neutrally buoyant?
- You are diving on Trimix 8/71 (O2/He). At what depth will you reach a critical intoxication limit? What will be the limiting gas?
For some of these questions, the "correct" answer will depend on the training agency. Anyway, enjoy!
