If you think that unmanned vehicles used for dangerous observation or even combat are something new, you are mistaken. Of course, you cannot expect the use of inertial sensors, Bluetooth communication, GPS or other microprocessor solutions in a version from 1917. A remotely guided torpedo with electric propulsion, but the propulsion was done by wires! At that time, battery technology was not sufficiently developed to adopt this solution. In the figure below, we have the project described by Gernsback, which had a power cable that unrolled when the torpedo headed towards the enemy. If we analyze how flying drones behave today, even carrying weapons, guided by GPS, we see how much we have evolved in terms of technology in less than a century.