Upload & Sell: Off
A couple of you were right on.
Whales sometimes leave "footprints" in the ocean as they travel. Until I saw it myself, I didn't know that anything else did. But why not? Manatees can be 9-feet long, and weigh well over 1,000 lbs. They live in (warm) shallow water, and they displace a lot of it- hence the "footprint."
I tried to see these strange, slow-moving vegetarian mammals in the wild, but all I ever saw were tiny noses occasionally snorkeling. So I went to a zoo where they were featured.
A spring-fed stream moved slowly through the property. Underwater fences kept the manatees from leaving, but permitted fish to come and go as they liked.
Here are two images from the shoreline of their habitat.
Tomorrow I'll post a couple that were taken from an underwater viewing tank.