Much to the delight of photographers, last winter was particularly frigid for Lake Michigan. Subzero temperatures caused "once in a lifetime" ice caves and gargantuan ice boulders on and around its shores, providing inspiration for magical images like this:
Now, the ice has melted away, revealing a brand-new photographic marvel. Last week, the water was so clear and so blue that the Coast Guard captured aerial photographs of shipwrecks along the Sleeping Bear Lakes National Seashore -- vessels that sank to the bottom of the lake centuries ago.
The wrecks, which become visible every so often due to environmental factors like beach erosion and varying water levels, are considered public property and can't be disturbed. The Coast Guard crew spotted them while on routine patrol and posted photos to the service's Facebook page.
"With Lake Michigan ice gone for the season the crystal clear, deep blue waters of northern Michigan are back (albeit still VERY VERY cold at an average of 38 degrees)," says the Coast Guard Facebook page. "We can call it 'Shipwreck Sunday.'"
The floors of the Great Lakes contain thousands of skeletons of ships dating back to the 1600s, when the first commercial sailboats began heading toward the Midwest.
"The vast expanse of these inland waterways provided a natural transportation system linking the Midwestern states and portions of Canada to the rest of the world," the Michigan Shipwreck Research Association explains on its website.
Take a look at more images of the wrecks, courtesy of the Coast Guard, below:
Ice cave photograph by Tom Auch. Ice boulders photograph by Ken Scott. All other images courtesy of the Coast Guard.