I kept being surprised seeing air-breathers deeper and deeper. I had no idea narwhals dove down to the depths where things live on hydro-thermal vents. Also that penguins have been near twice as deep as scuba divers.
The elephant seal really threw me for a loop, so I looked it up and [1]. It's not even close to accurate. I also couldn't verify any recorded dives of chinook salmon that deep either. A bit disappointing, this chart would be really cool if it was accurate