A semiconductor memory device and its operating method are disclosed. One of a plurality of predetermined valve lift profiles, each of which correspond to a respective range of engine operating load conditions and parameters, is selected dependent at least in part upon the engine operating load conditions and parameters. Embodiments of the present invention include a sonar device and a remote computing device configured to allow the sonar device to wirelessly communicate with the remote computing device and the remote computing device to connect to a database to register and receive information about real-time fishing hotspots.