Huntington-Ingalls Newport News Shipbuilding (NXDN) Unknown Talkgroups
From The RadioReference Wiki
Unidentified TG’s
TG 11 - GOV-xxxx GOV-0639
TG 16 - Encrypted, RID's GOV-xxxx, Navy or Marine Guards
TG 20- unknown comms aboard a vessel,
1340
Security is encrypted.