Water transmits sound much better than air, so the shockwave from any explosion (possibly including the tank's own gun) would rupture the eardrums of everyone inside.
They travel further, but higher frequencies slow down due to the medium.
It'd probably muffle some of the more damaging high frequency sound waves but there'd be some shockwaves of lower frequencies involved which might do something else to you
Given the high amplitude and nearness to the gun I'd guess nonlinear propagation would play a big part so that's interesting. IDK if that makes for a more intense shock front.
Fun tank fact! Due to a tendency for the M4 sherman to explode into flames when hit in the ammunition, it was devised to stow the ammo in water, coining the term "wet stowage"
Any ambulatory mecha would have massive motion sickness issues for the pilot whenever it walked. Suspending the operator in a fluid would possibly dampen the effects of bobbing around on the vestibular system and dampen shock from collisions or high-G turns. At least I imagine. I haven’t played Peace Walker but that’d be my reason for that to be in the design.
Huh, that actually makes sense! It's worth pointing out that it also allows for a woman to be piloting said mech in a bikini and Kojima has terminal coombrain so that might factor in too lmao (maybe I'm not giving him enough credit idk)
this is why mecha need to be smaller, agile, and well-coordinated, like a ballerina or someone taking that rich person ettiquette book-balancing-on-your-head-as-you-walk class, rather than a huge stompy brutish thing almost falling over with every step (looking at you, battletech)