I can’t, and I wasn’t going to. My argument was never about what Godzilla can or can’t do, it was about physics. Specifically, that you can’t move stuff around internally, without changing volume significantly, to change buoyancy.

Deballasting bone cavities is definitely an option. But to achieve the levels of buoyancy displayed by Godzilla, they’d need to be truly massive. Or he’s using paddling in tandem to help itself stay above water, akin to what dolphins do to hold most of their body above water.

Also, you can’t squeeze bones, so Godzilla needs an organ that would force discharge that ballast. Like sacks of highly compressed air, which are used to push out the water completely. This is similar to what submarines do.

Instead of bones, we could also just use your approach with organs. Emptying sacks of water and filling them with air. But either way, we need to discharge ballast, as I was saying originally. It’s a limitation of law of physics, and not a limitation of Godzilla’s abilities.

Source: I have a bachelor’s degree in Maritime Transportation and Navigation. Which is basically a BSc on “how to buoyancy right”.