What does navy mean?

Answer 1

That's a rate designation I've not seen in many years.

SOG2 is one of the earliest designations for a U.S. Navy Sonarman. There were several designations, the original just being "Soundman" (SoM):

SO - Sonarman

SOG - Sonarman (Sonar)

SOH - Sonarman (Harbor Defense)

SoM - Sonarman (Soundman)

SOMH - Sonarman (Harbor Defense)

While not specifically stated in U.S. Navy historical archives, the "G" likely stands for "Guns" as the current surface sonar rate, "STG", stands for "Sonar Technician, Guns". This is to differentiate between surface and submarine sonar rates, which share the same principles of Sonar, but vastly different tactics and equipment.

The equivalent submarine rating (my old rate) is STS, or Sonar Technician, Submarines.

The "2" after the SOG refers to the sailor's rank, in this case a 2nd Class Petty Officer.