An onboard marine clock is adjusted every day. A master clock shall be matched standard time by the radio rule. The adjustment is performed by manual operation at the time and these works are the duty of deck officer. The GPS receiver shall be include ocean going vessel. Network Time Protocol (NTP) uses the GPS time information. It can use shipboard LAN. The author designed the 40kHz radio transmitter for radio controlled clock and the program code of ship's time for the Unix embedded microcomputer. The accuracy of NTP server is efficient for shipboard LAN and the marine master clock and slave clocks. The transmitter for the radio clock onboard deliver the time information to the ordinary radio controlled clock within few meters. The authors installed some above integrated functions of the marine master clock to embedded computer. Finally, the generated time code can set some general radio controlled clocks by any ship's hour.
