One of the parks we visited when we were in Florida last month was the J. N. "Ding" Darling National Wildlife Refuge on Sanibel Island. We did the 4-mile hike hoping to see an alligator, but there was none around.
The highlights of our hike were mating horseshoe crabs and a couple of water snakes.
This was one of them.
Here is a closer shot of its head.
A display near the visitor center listed the mangrove water snake (Nerodia clarkii compressicauda) among the snakes that had recently been spotted in the park. According to A field guide to reptiles and amphibians (Conant & Collins, 1998), this snake, which they call the mangrove salt marsh snake, has "extremely variable" patterns and coloration, the latter varying from black to red. The book also states that "identification is often best accomplished on basis of habitat". So, based on that, I am tentatively identifying this snake as Nerodia clarkii compressicauda.
What was the 2nd snake?
Perhaps a black variant of the same species?