The Darter is a large, slim water bird with a long snake-like neck, sharp pointed bill, and long, rounded tail. Male birds are dark brownish black with glossy black upperwings, streaked and spotted white, silver-grey and brown. The strongly kinked neck has a white or pale brown stripe from the bill to where the neck kinks and the breast is chestnut brown. Females and immatures are grey-brown above, pale grey to white below, with a white neck stripe that is less distinct in young birds. The Darter is often seen swimming with only the snake-like neck visible above the water, or drying its wings while perched on a tree or stump over water. It has a cross-shaped silhouette when flying.