Submersible inspection device and redundant wireless communication with a base station

A submersible inspection device used for inspection of, for example, liquid cooled electrical transformers can include a number of separate cameras for imaging the internal structure of the transformer. The submersible can be configured to communicate to a base station using a number of wireless transmitters and receivers. Signals transmitted to the submersible include command signals useful to effect an action on the submersible but also a heartbeat signal to indicate health of the transmitted signal. A redundant channel selection logic is provided to switch from a channel which no longer receives a heartbeat to another channel that includes a current heartbeat. Multiple signals can be received and evaluated in software, and another signal received via a firmware radio.