>>715960206
>have no idea what modern military equipment can do
Tanks are not designed to be submersible - and even if they WERE, it would not be for extended periods of time like the Ray is capable of.
And despite what you might think, slapping "modern" on it doesn't mean it's magically capable of such feats. All tanks suffer from the same issues with the terrain that Rex gets around handily enough on its own, if it ever needs to move of its own accord.
To that end, there is not a single tank capable of loading up a WMD with the kind of potential Rex has, as the point of Rex is to disregard the need for aerially deployed ordinance using its shoulder-mounted railgun. That weapon alone defeats the purpose of most "modern weapons" as it was described to be capable of landing accurate hits on satellites without disclosing its location because the shells didn't use flares or propellant. It was never meant to be a "front-line" weapon you let just ANYONE see. No, that role goes to Ray for being a submersible attack weapon platform that only really attacks water-based infrastructure.

>>509363415
>never
Probably not in our lifetime.
There is a non-zero chance it could happen. Law of probability and all that.
It's just incredibly unlikely to happen while you or I are breathing air.