Argent, on a pile Tenné a bell of the first, two flaunches of the second, fretty of the field.
From a wreath Argent and Tenné a sea lion Or gorged with a collar barry of three Azure, Argent and Gules and grasping in dexter claw a lightning bolt barbed palewise Celeste.
VIDEO ET MONEO (I watch and warn).
In the orange and white of Signal Corps, the wedge-shaped pile is symbolic of the driving force of the organization, the bell representing contact. The V-shaped pile is also symbolic of victory; the interlacing or grill on each side represents the plotting functions of the organization.
The sea lion, adapted from the Philippine Presidential flag, commemorates the unit's campaign participation in the Philippines during World War II, and the collar reflects the colors of the Philippine Presidential Unit Citation as well as our national colors. Electronic capabilities are represented by the lightning bolt, whose barbs allude to combat readiness, while light blue refers to the South Seas and the geographical area of Philippines.
The coat of arms was originally approved for the 551st Signal Aircraft Warning Battalion on 20 December 1942. It was amended to correct the blazonry of the shield on 15 January 1943. It was redesignated for the 551st Signal Battalion effective 16 September 1986. The coat of arms was amended to include a crest on 11 February 1997.