The cold, clear freshwater of Lake Superior offers outstanding visibility for divers. Though there isn’t much to look at in the way of plant and animal life—the cold waters make for a pretty sterile-looking environment—the waters provide plenty of entertainment in the form of interesting underwater geologic formations and shipwrecks.

Ships have been running aground for well over a hundred years around the Keweenaw Peninsula, a navigational hazard if there ever was one. Within the 103-square-mile Keweenaw Underwater Preserve, divers can explore the Tioga, a freighter that ran aground near Eagle River in 1919, and the City of St. Joseph, which met its fate north of Eagle Harbor in 1942. Both ships lie in less than 40 feet of water, with large sections of the hull, deck machinery, and other artifacts clearly visible.

One of the Upper Peninsula’s oldest shipwrecks, the John Jacob Astor, lies just offshore from Copper Harbor, near the Fort Wilkins State Park Lighthouse Overlook. An Underwater Trail marks the location of the rudder, anchor, and other remnants of the Astor, which sank in 1844. For more information, contact the Michigan Underwater Preserve Council (800/970-8717, www.michiganpreserves.org).