That tower is filled with water. There's an air lock at the bottom. Put on a Steke Hood in the air lock and practice getting out of a disabled sub. Ho Ho Ho your way to the surface. Slow exhale all the way up to avoid the bends.
I would love to go in this tower. Is there a simulated sub-dive in there? The picture is a 10. The colors are so vibrant, the greens, the blues, the red. It is awesome. Focus is good, and the cropping is exceptional. Probably won't place where it should but in my book it's in the top 5. PTL