It doesn’t, the M163 in game is fully amphibious ready aside from the splash curtain
You can see from the image that the water doesn’t actually reach the level of the curtain and most soviet vehicles (BTR, BMD) do not have their intake/exhaust properly raised to allow for amphibious operations
iirc bmd 4 also have retractible snorkels like on the bmp, they can also install a longer snorkel but that is for more open sea conditions, so the only thing missing is really the animation and the rotation restriction.
As for the btr 82, it can operate without the snorkel aswel
Then I don’t see why the M163 needs to have the splash curtain to float
Well, the soviet vehicles doesnt have to isntall the snorkel, they just deploy them from inside of the vehicle, the vads need to instal the curtains as per the manual
But according to images and videos, the water level doesn’t reach the engine
The M-163 requires the same preparation to float as the normal M113, that is to say: almost none/none
