Diving ducks frequent large, deep lakes and rivers, as well as coastal bays and inlets. When launching into flight, most of this group patter along the water before becoming airborne. They feed by diving, often to considerable depths. Since their wings are smaller in proportion to the size and weight of their bodies, they have a more rapid wingbeat than puddle ducks.
Until fairly recently, this was the most frequent scoter in Ohio; now it is the scarcest. Rather than a decline in this species, changes in scoter status may reflect an increase in the other two species due to changing ecological conditions in Lake Erie.