Black spring water
What a great ride and ride report. I think your video captures told the story perfectly and you surely wouldn't have stopped to take pictures as often if you'd been using a regular camera. (I'm guessing you were using a GoPro?)
I grew up in northern Florida along the Suwannee River and when the rivers are up the springs turn black. I think it's that the runs back up and the clear spring water can't keep the river water pushed out. Based upon all the water you rode through it must have been after heavy rains/hurricane. I've seldom seen that much water on logging roads in Florida.
I certainly can see why you thought this was one of the best rides you've taken. It looks like a blast. So many different road conditions, all that water, little to no traffic (except for log trucks).
Thanks so much for sharing your ride. It brings back a lot of really great memories of growing up in Florida.