This research analyses the potential of Electrical Signature Analysis (ESA) as a means for condition monitoring of mechanical defects of induction motor driven thruster assemblies in the maritime industry. This is done by measuring the three phase current and voltage of three thrusters, with different health conditions, of a marine vessel sailing at different speeds. In this data, the mechanical behaviour of the machines is detected by plotting the frequency spectra of various electrical parameters, such as complex current and torque. After successfully identifying mechanical behaviour and defects, a suggested approach for the implementation of ESA as a means for condition monitoring is presented.