This image shows the arrival of Amethyst at Tamar in August 1949 after her detention on the Yangtze. Less well known is that the two RAF Sunderland flying boats that flew supply and rescue missions to the Amethyst were from RAF Kai Tak. They were not too successful due to heavy gunfire from the communists and they sustained damage. The movie of the incident that seems to be on UK TV every other week was filmed on the south coast of England near to Portsmouth and close viewing of the low lying backgrounds show a much different countryside to that on the Yangtze
Date picture taken
15 Aug 1949
Simon the cat
The IWM have an article about Simon, the Amethyst's famous cat: https://us11.campaign-archive.com/?e=ef2118cb6e&u=658d50dc0a76d8fea6561…
Thanks to James for the link.