The Vigilantes, 3rd Viper Squadron, is a long-estabilished unit in Colonial Fleet before the Cylon attack (Miniseries). Given that the squadron's logo adorns a wall in the quarters of Colonel Tigh (a commanding officer long removed from pilot service), it is likely that Tigh served as a member of the Vigilantes long ago as a Viper pilot in the first Cylon War.
Galactica pilot Lieutenant Kara "Starbuck" Thrace is a member of the Vigilantes (Act of Contrition).
Notes
The Vigilantes squadron logo is visible in both Colonel Saul Tigh's quarters and a pilot's ready room on Galactica.