The ROV uses three voltages: 3.3V, 5V and 12V. Of these, 5V and 12V must be provided to the main boards externally. I'm planning to provide power over the tether which means the voltages must be regulated once they arrive at the ROV. To keep the tether simple (2-wires) I intend to provide a voltage between 12 and 26V on the tether, the generate a stable 12V and 5V supply locally. Rather than build something to do this, I purchased a dual-voltage UBEC from Matek Systems. Below you see it powering the mated daughter and Raspberry PI boards.