Abstract: An unmanned vehicle can comprise a vehicle body configured to be at least partially submerged within liquid inside a conduit. At least one propeller can be coupled to the vehicle body. An actuator can be configured to effect movement of the at least one propeller to control motion of the unmanned vehicle within the liquid inside the conduit. A testing probe can be coupled to the vehicle body. The testing probe can optionally be an ultrasonic or microwave testing probe. An acoustic emission probe can be coupled to the vehicle body. A camera can be coupled to the vehicle body.