The pressure increases with increase of depth of water. The increase in pressure is 1 atm by 10 m increase of depth pf water. If this pressure falls on the diver directly, he will not tolerate it. Therefore, if a diver wants to go to large depth, he should wear the metallic cover. The pressure of water column falls on the metallic cover and the pressure inside the cover remains nearly equal to atmospheric pressure. Thus, by wearing metallic cover, the diver remains quite safe.
