But the submarine is a sealed container, with a big pressure difference between outside and inside. A skull isn’t.
Testicles redux. ::sigh::
But can they? I’m not aware of any observations supporting this.
I realized my mistake and used Arctic in my second polar bear example 
Take a tin can. Fill it full of water. Seal it. Take it down 1000 feet.
The tin can will not be crushed like a tin can. Neither will a steel can or an aluminum can.
If there are any air spaces in the tin can, those air spaces can be compressed and the tin can might bulge in by a small amount. But the water in the tin can will not be compressed by the water outside the tin can, any more than a given volume of water at the same depth is compressed by the water above it.
Yes, a can filled with air would be crushed. But a can filled with water would not be.
Note that the same can of water, could be easily crushed if you put it on the ground and put a 1000 foot column on top of it. It would split apart in microseconds. The exact same pressure has different results if the pressure is not evenly distributed.
A whale skull is not hundreds of times stronger than a human skull, and anyway, there are worms and soft-bodied creatures on the abyssal ocean floor a mile down. They aren’t crushed by the pressure, and they don’t have any sort of skeleton. The reason they aren’t crushed by the pressure is the same reason the water-filled can isn’t crushed. They don’t have any compressible air spaces, and they aren’t subjected to pressure changes. And so they live their wormy little lives at the bottom of the ocean.
What kills you when you are deep under the ocean are a couple of things. One, you aren’t able to expand your lungs, even with a scuba tank. So you asphyxiate. Creatures that live down there have gills, so that doesn’t matter, or their lungs can collapse, they don’t “hold their breath” while underwater the same way humans do, instead they rely on oxygen dissolved in their tissues. Two, you have other air-filled spaces all through your body, and these will collapse. Three, you’re experiencing pressure change, and so various substances in your body will change in solubility at different pressures. Note that high pressures tend to force gasses IN to solution, not out of solution. So you won’t have nitrogen forming bubbles in your tissues from the pressure, rather the reverse, you get nitrogen bubbles when you remove the pressure.
So no, your skull won’t be crushed like a beer can from the pressure, and neither will a beer can be crushed like a beer can. Yes, your lungs will collapse, your sinuses will collapse, your inner ears will collapse, any gas in your stomach and intestine will collapse. But 100 feet of water on your testicles won’t feel like Mike Tyson punched you in the testicles, because your testicles aren’t full of air. Note that if you set up a 100 foot tall pipe full of water and rested it on someone’s testicles, then yes, their testicles would be crushed like a beer can, same as a beer can would be crushed like a beer can.
Convincing post, except for this part:
The SCUBA tank (and its pressure regulator) allow you to breathe air at the same pressure as the ambient water. So your lungs expand on inhalation and contract on exhalation, just as you’d like them to.