Question

Which property of water allows large organisms, like the Blue Whale to swim in the ocean and not be crushed by their body weight?

Answer 1

Density. "When a whale submerges itself it releases air from its air bladder causing its overall density to increase. At the point where its density is > than the density of the water, it will sink. As it sinks the surrounding pressure increases but due to its higher density it can withstand the pressure - up to a point at least. At some point it must make an effort to move upward to breathe as well as avoid sinking to a depth at which the pressure becomes too high and crushes it.

Not the best explanation I'm sure but hopefully you get the idea."