Stealth for Underwater?

[HoneyBadger]

I'm pretty sure that adding flying or missle weapons (except for certain crossbows) to underwater creatures is pretty much unmoddable at this point, but is it possible for us to mod in stealth?

I can see flying and missles as being debatable (even though underwater creatures have evolved to basically do those things), but lots and lots of them use Stealth, in various forms, including pretty much the entire deep sea ecosystem-where sunlight can't reach.

So is this something currently denied to us as modders? Or are there simply no vanilla sea-critters with stealth?