A method and apparatus for classifying an image is proposed. A watercraft implementing the above method is also disclosed. Pressure transducers measure a first pressure immediately upstream of the seat, a second pressure between the seat and the orifice, and a third pressure immediately downstream of the orifice. A state-machine comprised in the PXI Express controller may be configured to interface with a chipset equally comprised in the PXI Express controller, to perform the control functions required to provide the support for the three different conditions. This arrangement enables a starter motor to be securely mounted to a power unit case with high rigidity, while enabling a reduction in the size of the internal combustion engine.