D-Day naval deceptions

Taxable, Glimmer and Big Drum
Part of Operation Bodyguard
A Harbour Defence Motor Launch, similar to those used during the operations
Operational scope	Tactical deception
Location	English Channel
Planned	1944
Planned by	London Controlling Section, Ops (B)
Target	Cap d'Antifer, Pas-de-Calais, Normandy
Date	5–6 June 1944
Executed by	No. 617 "Dam Busters" Squadron No. 218 "Gold Coast" Squadron Royal Naval Reserve
Outcome	Limited success in deceiving the Axis as to Allied intentions

Operations Taxable, Glimmer and Big Drum were tactical military deceptions conducted on 6 June 1944 in support of the Allied landings in Normandy. The operations formed the naval component of Operation Bodyguard, a wider series of tactical and strategic deceptions surrounding the invasion.

Small boats, along with aircraft from RAF Bomber Command, simulated invasion fleets approaching Cap d'Antifer, Pas-de-Calais and Normandy. Glimmer and Taxable played on the German belief, amplified by Allied deception efforts over the preceding months, that the main invasion force would land in the Calais region. Big Drum was positioned on the western flank of the real invasion force to try to confuse German forces about the scale of the landings. These operations complemented Operation Titanic, which was intended to confuse the Germans about the D-Day airborne forces.

It is unclear whether the operations were successful, due to the complexity of their execution, poor weather, and lack of response from German forces. It is possible that they contributed to the overall confusion of D-Day as part of the wider Bodyguard plan.