Drone that turns into submarine
http://www.iflscience.com/technology/boeings-new-flying-swimming-drone-patent-has-been-released
http://www.iflscience.com/technology/boeings-new-flying-swimming-drone-patent-has-been-released
The rising use of drones and concerns that come along with it, forces authorities to develop systems such as sending it back to its source. See here: https://www.yahoo.com/tech/s/exclusive-u-government-police-working-counter-drone-system-050355777.html