No, because it was not on an RAF boat...
RAF calling their flag an "Ensign" is as ridiculous...
Well according to
this it is an ensign and its all the Admiralty's fault.
The Royal Air Force Ensign. The Royal Air Force Ensign was introduced in 1920 amid much controversy. This was because it involved the Admiralty, The War Office and the Air Ministry. The Air Council had decided that the newly formed Royal Air Force should fly its own flag from its stations. This did not find much favour with the Admiralty who have the right to veto the introduction of any new flag intended for use either on land or at sea anywhere within the British territories.
The Air Council though, were most insistent and so the Admiralty reluctantly conceded, stating that if the Royal Air Force was intent on having its own flag, then it should adopt the Union Flag with some appropriate device attached to it.
The Air Council did not like this idea and sent a sketch of its proposed design to the Admiralty, which was a White Ensign minus the St George's Cross. Although the War Office had no objection to this, the Admiralty did and rejected the submission on the grounds that the White Ensign, along with the Blue and Red Ensigns, were reserved for the Royal Naval Service exclusively and any use of them not connected with the Royal Navy was to be forbidden.