When I showed my dad this photo from the Lake of the Clouds at Porcupine Mountains Wilderness State Park, he commented that it looked like sea corral. I had not noticed that when I was shooting the photo nor when I was editing it on the computer a few days later. However, after my dad compared it to an underwater scene, I could not agree more.
F2.8 at 1/250, ISO 100, 300mm lens at 300mm