Lieutenant Commander Buchanan had been invalided out of the service at the outbreak of war. On 29 May 1940, upon hearing a broadcast that the Admiralty sought enginemen for yachts, he promptly applied. The following day, he reported to Robinson's yard at Oulton Broad and assumed responsibility for the engines of the estuary cruiser Elvin. The vessel was powered by two 25hp Highlander petrol/paraffin motors, which required Buchanan's full expertise.

The crew for the initial voyage to Ramsgate comprised Lieutenant Commander Buchanan, a young Sub-Lieutenant RNVR, a retired fisherman from Aberdeen, a Lowestoft longshoreman, and Hackforth-Jones, a writer of yachting stories who had served with Winston Churchill's battalion during the First World War. Although they reached Ramsgate, a miscommunication resulted in their return to Lowestoft. There, they received new orders to proceed once again to Ramsgate.

On their second attempt, the crew departed for Dunkirk despite official reluctance due to their civilian status, the vessel's slow speed, and the fact that it flew the Red Ensign. When they overheard a Chief Petty Officer confirm their departure, they cut the mooring lines and left. The dock commander responded with a shrug, followed by a shower of first aid kits into their cockpit.

Elvin departed late on the evening of 2 June 1940 and arrived at Dunkirk at first light. Without charts, the crew navigated by following other vessels and steering towards the glare of fires and shell bursts. During the crossing, the starboard engine failed but was promptly repaired by Buchanan. Upon arrival, they moored alongside the eastern pier, where a column of soldiers awaited embarkation. When a French officer inquired about the number of soldiers, Buchanan, unable to recall the French term for '25', responded with "trente" (thirty), which exceeded the vessel's comfortable capacity. Nevertheless, additional soldiers were admitted after a Frenchman pleaded "mon ami!"

The Elvin then followed an overloaded open boat towing a whaler, heading for a destroyer. Concerned about the vessel's top-heaviness and risk of capsizing, they navigated through wreckage obstructing the approaches. Upon finding the destroyer had departed, they pursued French minesweepers but were unable to keep pace. Ultimately, they returned to Ramsgate, navigating without knowledge of the swept channel. Their shallow draft reduced the risk from mines, but flotsam presented a hazard.

At Ramsgate, Elvin disembarked 25 French and 8 British troops on the North-East wall.

Post-War Service and Restoration

Following the war, Elvin was transferred to Portugal. At various times, she was owned by the Marquis of Pombal and the chairman of a cement firm in Lisbon. In August 2008, the vessel returned to the United Kingdom and underwent extensive restoration at a yard on the lower Thames.

Notable Events and Voyages

• 2012: Participated in the Queen's Diamond Jubilee Pageant on the Thames.
• 2015: Took part in the 75th anniversary return to Dunkirk.
• 2016: Featured in Christopher Nolan's film Dunkirk.
• 2017: Completed a three-month circumnavigation of Great Britain, including Northern Ireland and the Isle of Man. The route encompassed the Thames, Channel Isles, Land's End, the Welsh coast, Isle of Man, Southern and Northern Ireland, numerous Scottish Isles, Outer Hebrides, Cape Wrath, Orkneys, Shetlands, and returned down the east coast to the Thames.