After completion, she was dismantled and shipped to Hong Kong for re-assembly before being deployed for service on the China station, on the Yangtze River to provide protection for British commerce and nationals.

HMS Peterel was designed and equipped to patrol the upper reaches of the river (she had a shallow draft and her primary armament was a pair of 3-inch guns).

One river gunboat, HMS Peterel, was retained in Shanghai to provide a token British military presence that it was hoped would dissuade the Japanese (who had already occupied most of the city) from moving against the International Settlement there.

With her reduced complement, she was capable of steaming for only a limited period of time and her main armament had been disabled to lessen her value to the Japanese in the event of capture.

Polkinghorn attempted to stall for time, in order for the demolition fuses to be lit and the code books to be passed down a special chute to be burned in the boiler room.

The Royal Navy survivors from HMS Peterel (including Polkinghorn) were moved amongst the Hongchew, Kiang Wang and Woosung internment camps in China.

Three of the crew of HMS Peterel were onshore during the Japanese attack; two were captured but the third, PO Telegraphist James Cuming, remained at large in Shanghai for the duration of the war, working for a Sino-American spy ring.

The citation (published in The London Gazette on 23 October 1945) reads: "For great courage, determination and tenacity in fighting his ship, HMS Peterel, when attacked by overwhelming Japanese forces at Shanghai on 8th December 1941".