This is just idle observation, but when you ascend the air in your lungs expands and you are supposed to continuously exhale to prevent lung rupture. Supposedly if you start with a full pair of lungs, you can ascend pretty much from the bottom of the ocean on just one breath because of this.
Also somewhat related, the deeper you go the less time your tank lasts. From what I remember, at 100m, a "5 minute tank" is probably similar in size to a standard scuba tank.
Also somewhat related, the deeper you go the less time your tank lasts. From what I remember, at 100m, a "5 minute tank" is probably similar in size to a standard scuba tank.