The John Canny video of his trip to Cape York (Part 1) shows you part of the PDR:
View: https://youtu.be/a3bP6ur6A-M?t=1948
I just watched part 3 while having a morning tea break. Unfortunately you can't see any footage of the 4th vehicle crossing
The first three have snorkels/RAI's and it looks pretty deep.
Unfortunately no footage of the 4th vehicle was taken.
It would have been interesting to see how a vehicle with no snorkel or RAI handled water this deep.
The video just cuts to a splash screen with a simple large statement with an !!!!!!