Yeh, it all comes down to pressure equalization. I don't remember what the depth record for a man diving, without a submarine like capsule, so I'm talking about wet suit/ deep diving suit or bell. A bell subjects the man to the full pressure of the water, as it works by pumping air at high enough pressure to drive the water out the open bottom.
This is where nitrogen in the blood is a problem, and why divers must decompress.
A quick search shows a scuba record at over 1000 ft
You have to be careful looking this up, tho......The Navy has a new type suit called an "atmospheric" suit which allows the diver to exist at "sea level" pressure. That record is about 2000 ft.
the old "traditional" deep sea suits with the huge brass helmet subjected the body to same pressure (ballooned air) as the see around them. By the way there are incidents of those killing people---when the air in /out system valves stuck / malfunctioned/ or were misadjusted, and when ascending, the reducing pressure of the sea could "balloon" the suit making it impossible to more your arms and adjust the valving. From there you got to wait until the suit exploded due to higher air pressure/ reducing sea pressure, and then.......you were done.
