Two adults on stand up paddle board (SUP) observe hole melted in iceberg on Bear Lake in Kenai Fjords National Park, Alaska.

One man on stand up paddle board (SUP) paddles past hole melted in iceberg on Bear Lake in Kenai Fjords National Park, Alaska.

One man on stand up paddle board (SUP) maneuvers in an iceberg cavern on Bear Lake in Kenai Fjords National Park, Alaska.