The Navy Service Medal was a decoration of the Republic of Vietnam. established by Decree No. 154 of 12 May 1964, it was intended to recognise members of the South Vietnamese Navy who had completed a set number of years of service.
The medal was divided into four classes indicated by a device on the ribbon bar:
During its existence, the medal went through three designs:
Type 1: This design features a light blue disc depicting a silver whale swimming in light blue waves beneath a light blue sky. The disc surmounted a golden compass rose, which in turn surmounted a silver anchor. The reverse was plain. The suspension device was a standard trapezoid device.
Type 2: This design was a golden anchor surmounted by a six-spoked ship's wheel; the reverse was either plain or had the words "VIá»ÂT-NAM" surrounded by the words "HẢI-VỤ Bá»ÂI-TINH". The suspension device was a standard trapezoid device.
Type 3: This design features a light blue disc depicting a silver whale swimming in light blue waves beneath a light blue sky. The disc surmounted a golden compass rose, which in turn was surrounded by a silver wreath. The reverse was inscribed "VIá»ÂT-NAM". The suspension device was a fouled anchor.