scrapdizzy:
It does not take a large pressure differential to rupture an eardrum. A descent 10-20ft without clearing could do it easily. I read about people having uncontrolled or poor descents here all the time, in class and otherwise. I read about people having uncontrolled ascents here frequently.
From some of the class reports I've read here, I am amazed more divers aren't hurt.
I watched two divers a couple of months ago at a local diving spot. Husband and wife I presume, with an instructor. They were trying to descend down a line. Wife descended a bit and came back up. Husband was determined to do it. When he came back up he had blood in his mask. Site depth was 70ft max, instructor was about 25ft below the surface, when I was on ascent.
The next month, I saw 3 certified divers at another local site. All trying to descend into a cavern basin. The sides are VERY silty. One woman, lost control of her buyancy after riding the inflator and dumps like an elevator, and slid down the side of the basin. And a site known for about 200ft of vis, went to about 20. She and her friends proceeded to stand on the bottom of the basin, and then they proceeded to enter the cavern with 1 light between the three.
I have come to the conclusion that either instruction that these people is exceptionally poor, or they have totally forgotten what they were taught. Thus I am not surprised to hear about burst eardrums or other maladys that generally arise from a lack of buoyancy control.
I am sorry your friend got hurt. It's never pleasant. Sadly its all too common. I hope your friend is able to return to diving if they so choose, but I hope they gain better control of buoyancy before venturing outside the confines of a pool.