There were fewer losses of major vessels on 30 May compared to the previous day, due in part to the decision of Capt Wm. Tennant, SNO Dunkirk, to only allow one destroyer at a time to enter the harbour. This ensured that there was less congestion and fewer targets were presented to German aircraft.
HMS King Orry (Cdr J. Elliot, RNR), a passenger steamer from the Isle of Man Steam Packet company requisitioned by the Royal Navy for use as an Armed Boarding Vessel (ABV) in both the First and Second World War, attacked and badly damaged by German dive bombers. Scuttled clear of the harbour.
French destroyer Bourrasque struck a mine off Nieuwpoort, Beligium (ironically, a French-laid minefield). Survivors taken off by French torpedo boat Branlebas, Admiralty drifter Yorkshire Lass, and armed trawler HMT Ut Prosim.