Eli5, how is it that Scuba divers typically have to squeeze their nose and blow to equalize the pressure in their ears every few feet, but those who free dive can sink 20-30 feet in 10 seconds, and be fine while not visually equalizing?

Question

Is the ability to breathe what changes this, or is there some other technique behind it?

In: 55

Answer 1

I can open my Eustachian tubes at will which means that I can drop like a rock all the way down to 120ft without ‘clearing’.