Back in my teenage years, I was a lifeguard at a church camp for a couple of summers. Being a paid, permanent staff, at the end of all the days activities, when the kids were sent back to the cabins to get ready for bed, we were released from any activities, and could do whatever we wanted (within reason of course).
One evening I decided to walk down to the lake and sit on the dock and stargaze for a while. I hadn't been there more than 5 minutes when I heard a splash at the shoreline about 30 feet from the end of the dock. I turned a looked, but didn't see anything. After convincing myself it was just a fish going after a smaller fish, I turned back around and looked out over the lake. Just then I see 2 orange eyes swim by about 10 feet from me. I decided that I had stargazed enough that night and left rather quickly.
The next morning on the other side of the lake, that same alligator was sunning itself on the dock when those kids came down to swim. Needless to say none of the Middle School kids from that camp wanted to swim that day.