The Apostle Islands National Lakeshore has become a world-class destination for sea kayaking, but some of the most popular attractions can also be treacherous. Under certain conditions, the sea caves can quickly change from awe-inspiring to terrifying. As waves roll into and reflect off of the cave walls, they can intensify and capsize even experienced kayakers. Once out of their boats, paddlers face the threat of hypothermia in water temperatures that hover in the mid-40s for most of the summer and rarely exceed 60 degrees. In addition, the surrounding steep cliffs make seeking safety on shore nearly impossible.

Read the full story at the Aquatic Sciences Chronicle