While large turtles are pretty slow on land due to their size and weight, ... The fastest human swimmer managed a comparatively feeble 8.6 km/h! 2. They hung out with dinosaurs.

New Shape-Shifting Robot Turtle Can Navigate Land and Sea. ... At its fastest, ART can “swim” at 0.083 meters per second (m/s) and walk at 0.03 m/s.