Georgetown, Guyana's largest seaport and capital, is situated on the east bank of the river's mouth.

The river's deep brown color is primarily the result of the massive quantities of silt carried from upriver by the powerful currents.

So powerful are these currents, that the ocean retains the Demerara's brown color for a considerable distance out to sea.

The islands Inver, Borsselen, and Biesen are found 25 to 30 kilometres (15 to 20 mi) from the mouth.

The colony founded the sugarcane industry that continues to thrive today.