Question

In snorkeling a swimmer breathes by means of a tube that extends above the water level. A) Why is the tube restricted to about 20 centimeters? That is, what is the acute danger in using a longer tube? b) So under a certain depth people now scuba dive. When a scuba diver is brought back to the water surface, why must the diver wait at certain depths for set time intervals instead of being brought up continuously?

Answer 1

The snorkeling tube length is restricted to 20 cm because it might be not easy for a person to breath at depth of 2 feet. The deeper the person goes then the harder is for him/her to breathe. Because the pressure of water on the person increases with depth. This pressure is compressing on our chest causing difficulty inhaling air. Also longer the tube the larger possibility of reintroduction of CO₂. Since the same tube is used for inhaling and exhaling some of the exhaled CO₂ might be reintroduced into lungs which might cause harm at larger amounts.

B)

It is to make the scuba driver adapt gradually for the change in pressure. At the bottom of the ocean the pressure is too high because of it a the air inside body is under a heavy pressure which on rapid escalation will be released into blood stream with air bubbles which are extremely dangerous. So it is necessary to slow down while returning to the surface