The two Vigilant Platoons, X and Y, were formed in 1966 to provide anti tank support to the 16th Parachute Brigade utilising the Vigilant wire guided missile.

The two platoons each had about twenty troops, from all three parachute battalions, and were barracked at brigade headquarters, along with elements of 9 Parachute Squadron RE and 216 (Parachute) Signals Squadron. Additionally, time was also spent training with the 7th Parachute Regiment Royal Horse Artillery.

The Vigilant Platoons were also called upon to provide additional manpower for battalions serving on operations, including Northern Ireland.