We had picked up the SAR Force Commander at Chelsea Barracks and flew down the Mall at 300' before making our approach and landing at the back of the Palace where there is a LS.
All the way down the Mall, I was thinking 'I'm sure we shouldn't be doing this' but it was all approved and above board.
Coming back out at night after the cocktail party - we were the only ones not quaffing the Queen's champagne - on NVG was pretty spectacular as well.