Identificaciones de krechols13

Lackluster photos, but I think between descriptions and photos it can be ID'd.

Black and white beak, brownish body, brown head fading to grey. Standard duck size (compared to Mallard,) perhaps 10-15% smaller. Champion of hide and seek, dives & disappears for 5+ minutes at a time, potentially finding cover in cattails growing along the pond's edge. Seen in an (artifical) pond at a park in central NJ, USA.