Nonvenomous Northern Watersnake (Nerodia sipedon) that was not spooked at all. A lot of times they will easily get spooked and they are gone into the water. Non venomous water snakes are the snakes that dropping into boats when people are claiming those snakes to be cottonmouths. Description: Northern watersnakes range in size from 24 to 55 in (61-140 cm). They are fairly dark-colored snakes and may be brown, tan or grayish. The coloration is much more vivid in young and wet specimens. Their bac