There are these small water patches that don't freeze all winter long. They occur in drumlin- and esker-festooned tidal flats between Arviat and Whale Cove, west shore of Hudson Bay. This one is in a channel between bays and likely kept open by tidal currents.
I've been looking down at some half dozen scattered water patches in this locale for years and finally got lucky this winter. It was a clear day with a crisp wind providing a visible icy plume blowing offshore from a black patch of open water. Mile-high west-facing aerial view.