Highest I've ever seen cows in water is where it is just over their backs. I would assume they cannot go any further or swim due to their size, however I've been wrong before LOL.

The ground under foot (hoof) there is also mushy, which is another reason I never figured they would venture far out there in the first place. Our biggest heifer probably goes up to my chest, so the last panel in the water access point being up to my nose is probably good? Or not?

Just know I shouldn't have taught them how to build poncho rafts... LOL