Tony,
Thanks for those interesting Pathé links.
The couple of Princess Margaret with the Sea Rangers reminded me that my sister had been one, but a few years later. I know she went to a few Sea Ranger gatherings, but can't remember if she was ever on Foudroyant. I'll have to ask her!
I thought that the other ship was the Implacable, when I saw the clip before, but wasn't sure. I liked the enormous ensign that Foudroyant sported – a bit like the huge ones in the previous centuries. I bet no-one stayed in its vicinity for long that day!
Thanks for adding the video link inline to my post – I certainly don't mind.