A propeller shaft is supported on the stern end of a ship hull by a bearing within which optic fiber cables are embedded in close spaced relation to the outer cylindrical surface of a bearing supported portion of the propeller shaft for a monitoring wear thereof with maximum accuracy. An optical data acquisition system having a light source and a graphic display is operatively connected to the optic fiber cables through inserted optic connector cables to transmit light from the light source as a signal medium into the bearing so as to render the optic fiber cables therein operative as sensors to detect and measure wear of the entire bearing portion of the propeller shaft surface being thereby monitored. Wear measurement optical signals within the wear sensing cables are then transmitted back to the data acquisition system through the optic connector cables for display of the shaft bearing wear measurements.