Here is an interesting video with a Rivian R1T all-electric pickup truck water fording in Mojave, California.
It was shared by Nuwan Rajapakse, who, considering the description of "first water crossing with my new R1T, is potentially a happy driver of the vehicle.
The R1T does not look to be submerged as much as in the case of Rivian's internal tests (see video below), but it was a substantial obstacle.
When launching the R1T, Rivian announced that the wading depth is 3+ ft (more than 0.91 m).
In general, all-electric vehicles (even stock) are considered capable of driving in water, which normally would be a no-go for conventional, internal combustion engine (ICE) vehicles.
The main reason for that is the lack of the engine and its air intakes, which in off-road ICE vehicles, must be above the water. There might be other reasons too, including the exhaust system and sealing.
Despite the advantage of BEVs over ICE, manufacturers warn owners to not exceed the limits of wading depth or time submerged.
In extreme cases, with a special treatment, EVs could be turned into a submarine, which was demonstrated with the use of a Tesla Model S Plaid several months ago (after some fails):
