System for and method of controlling watercraft

A system for controlling a watercraft, the system comprising:

• a data communication module to perform wireless communication with an external computer;
• a device system connected to the data communication module and including at least one electric device;
• an electric power supply including a battery and operable to provide electric power to the data communication module and the device system;
• and
• a controller configured or programmed to control providing electric power to the data communication module and the device system by the electric power supply;
• wherein
• the controller is configured or programmed to switch between a first mode and a second mode;
• the controller is configured or programmed to provide electric power to the data communication module by the electric power supply in the first mode during both activation and deactivation of the device system;
• and
• the controller is configured or programmed to provide electric power to the data communication module by the electric power supply in the second mode during the activation of the device system, and to stop providing electric power to the data communication module by the electric power supply in the second mode during the deactivation of the device system.