Elizabeth Green was among the first privately owned rescue vessels to assist in the evacuation of Dunkirk during World War II. On her second voyage, she was one of the last ships to depart the beaches. Her service is exceptionally well documented, notably through the detailed log kept by Sub-Lieutenant E. T. Garside, RNVR, who recorded an hour-by-hour account of his first nine days of active duty.

The vessel’s involvement began at 18:05 on 28 May 1940, when she departed Sheerness Basin with a crew consisting of one seaman and two stokers, towing a whaler and bound for Dover. After losing contact with her convoy due to engine failure, repairs were successfully made. The following morning, Elizabeth Green refuelled and set course for Dunkirk, arriving at 15:30 amidst heavy enemy bombardment.

She was directed to La Panne beach, where she commenced towing whalers filled with troops to larger ships positioned offshore. At 16:00, the paddle steamer Crested Eagle sank nearby. By 18:00, the vessel Viewfinder was dragged ashore by Belgian troops and was never refloated. At 19:00, the Hanora fouled her propeller and was abandoned; Elizabeth Green rescued her crew and transferred them to the minesweeper Lydd. Finally, at 21:20, Elizabeth Green departed La Panne fully loaded, accompanied by the motor yacht Advance. Encountering thick fog en route, the vessels anchored in Pegwell Bay before entering Ramsgate at 06:50, having spent thirty-six hours at sea and off the beaches without rest.

Sub-Lieutenant Garside subsequently made another journey to Dunkirk aboard the RAF launch Andover II. On 4 June, he was reassigned to Elizabeth Green, which departed Ramsgate at 16:00 with a crew of four seamen and an interpreter. The mission was to rescue remaining French soldiers stranded at the end of the Dunkirk jetty. Elizabeth Green was towed by the tug Rania, along with the Clacton lifeboat. By 21:50, the tow-rope parted, and Elizabeth Green proceeded under her own power.

This final night of the evacuation was marked by extremely challenging conditions. The crews faced constant air attacks, shelling, and mines, enduring days without sleep or proper nourishment. The waters near the French coast were cluttered with debris, stranded and sinking ships, and bodies. Vessels of various sizes, some with disabled steering, maneuvered dangerously to evade attacks from the air, German E-boats, and each other. Collisions were frequent, followed by urgent efforts to rescue survivors.

Elizabeth Green successfully reached the Quai Jules Faure in Dunkirk harbour. She carried a 30-rung ladder from England, which, according to stoker D.R. Nichol, was placed from the deck to the sea wall to assist approximately twenty French soldiers in climbing aboard. On the return journey, the engine seized but was restarted, allowing the vessel to head for Ramsgate. As sea conditions worsened, the French officer in charge of the troops became ill. Crew members provided plates in an attempt to manage the situation, though the cleanup was difficult. Within an hour, the engine failed again off Broadstairs but was repaired, and Elizabeth Green finally arrived at Sheerness at 15:30, twenty-four hours after departing for Dunkirk, having endured minimal food and rest.

Lieutenant Garside, on his third trip aboard Elizabeth Green, was commended for his exemplary courage and composure and was awarded the Distinguished Service Cross.

Following the evacuation, Elizabeth Green was assigned to mine-spotting duties and was frequently berthed at Sheerness alongside HMS MMS 41, a minesweeper commanded by Lt. Commander E. T. Garside DSC. After the war, the vessel was purchased by the late John Knight, former Hon. Archivist and past Commodore of the Association of Dunkirk Little Ships (A.D.L.S.). Elizabeth Green featured in a television programme about Dunkirk and appeared in video footage of the first commemorative cruise in 1965.

As of 2018, Elizabeth Green has been relocated to Chertsey and awaits further restoration.