Swim? Anyone?

An interesting tale, or is it “tail”?
Just after dinner, maybe 7 PM, I looked out at the pool and spotted a large snake enjoying the poolside life. He had his tail in the water but since he was close to 5’ long, most of his body was on the deck. And he was really a magnificent specimen; maybe 3” in diameter. But what kind of a snake was he? I went out to investigate and determined that he wasn’t a rattlesnake. I have forgotten all that I once knew about snakes so I was unable to give him an identity. Using my pool net, I encouraged him to move along and out of the yard. He was quite unhappy about this procedure and hissed loudly, striking at the net in frustration. Once he was gone, I turned and spotted another one at the opposite end of the pool! Same thing…tail in the water. This one was smaller, maybe only 3’ in length. So once more I escorted a snake from the yard. Now I wonder; what kind were they and do they always come to the pool about that time? I guess I can Google snake images and with that information I should be able to figure out what kind they were. The good news is that snakes eat mice…lots of mice!