To reply to the rumors-
BOTH 4Runners survived the day. Hopefully Ed will surface to confirm this.
The "Pond" depth was probably up to the top of the wheel wells but due to the entry angle the nose of the truck sinks in as you enter it. It then levels out a bit, and the photo was taken just as the nose of the truck (or perhaps bow of the boat in this case

) started to come up from the steeper entry angle.
Fireteacher mentions the speed at which I entered it. It was actually not that fast of an entry- the bottom of the "pond" is fairly rocky so it has to be negotiated relatively slowly. The "severity" of the pic is due to the entry angle.
As fireteacher mentions, you can form a bow wave to "follow" through the water that will create a small area of water behind it that is lower in height in which the engine compartment can "hide" in from deeper water.
The speed at which I entered the water was the proper speed and did in fact, form a bow wave. I was actually able to fish from it as I drove through
I've never had any long term mechanical problems with that water crossing. Although that was definitely the deepest it's ever been.
And yes, that's a Garmin Nuvi 350 GPS unit screenshot.