“When we want robots to explore the deep ocean, especially in swarms, it’s almost impossible to control them with a joystick from 20,000 feet away at the surface,” said Professor John Dabiri, an expert in aeronautics and mechanical engineering at CalTech. “We also can’t feed them data about the local ocean currents they need to navigate because we can’t detect them from the surface.

“Instead, at a certain point we need ocean-borne drones to be able to make decisions about how to move for themselves.”

These drones would need to be able to make decisions on their own about where to go, but also the most efficient way to get there. To do so, they will likely only have data that they can gather themselves: information about the water currents they are currently experiencing. 

The engineers, therefore, developed an algorithm that would allow the drone to steer itself while swimming. For this, they used reinforcement leaning networks. Compared to conventional...