No, not the Boat Show, that was earlier this month. Reason for her visit doesn't seem to be public. Another vessel in there too.
Larger vessels (such as Iron Duke) are usually brought through the dock past the runway when the airport is closed - indeed Iron Duke was in before dawn this morning. It causes a mess with traffic as queues quickly build up at the Connaught Bridge.
But it's not an absolute rule. One of the large sunseeker type boats that came to the boat show went through on a mid afternoon on a weekday when there was a natural lull in flight movements.