ROVs (remotely operated vehicles) let us explore bodies of water and it is hard not to be excited by the possibilities. But traditional ROVs cost a lot of money and often require serious expertise to operate and maintain. Luckily there are affordable alternatives, such as this DIY underwater rover designed by Science Buddies’ Ben Finio.

Finio created this ROV specifically for educational purposes and so it accommodates a relatively small classroom budget. For about $100-150, a school science club can build this device and start exploring the depths. 

In order to keep the costs down, Finio used as many everyday parts as possible. The hull, for example, is a food storage container and the weights to bring the vehicle close to neutral buoyancy are steel bar stock. This design doesn’t include a ballasts or thrusters to alter depth (it can only steer left or right), so users will have to experiment with the weights to reach the desired depth.

This ROV has two thrusters for propulsion and steering. Those are electric DC motors controlled by an Arduino UNO Rev3 board through H-bridge drivers. Power comes from an onboard lithium battery and users pilot the craft with a remote control connected via a tether. That remote has two joysticks, each with one axis tied to one motor’s power.

Finio suggests attaching a GoPro (or any other action camera) to the vessel to record the underwater action.