Singaporean researchers created this underwater drone that swims like a manta ray. Flexible fins give it the ability to glide through turbulent seas and while there have been other crafts built with a similar capabilities, the MantaDroid is the first to use just one motor for each fin. It uses the water around it to help control the motion of the fin and drive the drone forward. It can move about .7 meters per second and you’ve got to check out the video to see how similar it moves to a true manta.