An azimuth thruster comprising apparatus (10, 101, 102, 103) for transferring electrical energy, comprising: a stationary part having a first surface oriented perpendicular to a longitudinal axis of the azimuth thruster and a perimeter extending around the first surface, the stationary part being mountable to a vessel; a rotatable part having a second surface oriented perpendicular to the longitudinal axis and positioned adjacent the first surface of the stationary part, and a perimeter extending around the second surface, the second surface being arranged to rotate relative to the first surface, the first surface and the second surface facing each other and thereby defining a gap there between; wherein the apparatus (10, 101, 102, 103) for transferring electrical energy comprises: a first inductor, positioned on a first part of the first surface, to provide a magnetic field, the first part extending along only a portion of the perimeter of the first surface; a second inductor, positioned on a second part of the second surface, the second part extending along only a portion of the perimeter of the second surface, the second inductor being arranged to generate an electrical current from the magnetic field when the first part and the second part are at least partially aligned, thereby forming a transformer transferring electrical energy across the gap. a stationary part having a first surface oriented perpendicular to a longitudinal axis of the azimuth thruster and a perimeter extending around the first surface, the stationary part being mountable to a vessel; a rotatable part having a second surface oriented perpendicular to the longitudinal axis and positioned adjacent the first surface of the stationary part, and a perimeter extending around the second surface, the second surface being arranged to rotate relative to the first surface, the first surface and the second surface facing each other and thereby defining a gap there between; wherein the apparatus (10, 101, 102, 103) for transferring electrical energy comprises: a first inductor, positioned on a first part of the first surface, to provide a magnetic field, the first part extending along only a portion of the perimeter of the first surface; a second inductor, positioned on a second part of the second surface, the second part extending along only a portion of the perimeter of the second surface, the second inductor being arranged to generate an electrical current from the magnetic field when the first part and the second part are at least partially aligned, thereby forming a transformer transferring electrical energy across the gap. a first inductor, positioned on a first part of the first surface, to provide a magnetic field, the first part extending along only a portion of the perimeter of the first surface; a second inductor, positioned on a second part of the second surface, the second part extending along only a portion of the perimeter of the second surface, the second inductor being arranged to generate an electrical current from the magnetic field when the first part and the second part are at least partially aligned, thereby forming a transformer transferring electrical energy across the gap.