The Teddington boatyard of Tough Brothers played a significant role in the Dunkirk evacuation. It served as a collection point for some of the hastily requisitioned boats from the upper Thames, which then set out in convoy from Teddington on the initial leg of their journey. Records from Tough Brothers, including Douglas Tough's handwritten notes, document the civilian boatmen from around London assigned to individual vessels. These names frequently reappear as these men served on various boats under naval command.

Following the Dunkirk operations, some surviving vessels were towed back by Tough Brothers' watermen from Ramsgate and Margate harbours and stored pending either requisition by the Admiralty for auxiliary service or return to their owners, if they could be located. Some owners were displeased to find their boats used without prior knowledge and, in some cases, were unable to reclaim them until the Admiralty determined their future. Tough Brothers also faced challenges tracing owners of boats no longer required by the Navy. Additionally, the Admiralty imposed a deadline after which it would no longer cover storage charges. Mount's Wharf, where the boats were stored on behalf of Tough Brothers, employed a night watchman to guard against fire risks from incendiary bombs, leading to increased storage fees. Resolving these issues took several months, during which Tough Brothers also undertook repairs on many damaged vessels.

Although Minnehaha’s specific activities at Dunkirk are unknown, after the evacuation she was discovered by Douglas Tough in Ramsgate harbour with her wheelhouse badly burnt and the crew’s charts still in the chart drawer. The vessel was towed to Teddington, where the yard constructed a new wheelhouse and removed the aft cabin. She was renamed Tigris III and used by the yard as a tug.

In 1944, Douglas Tough purchased the boat from the yard, converted her back to a motor cruiser, and renamed her Thamesa. With the necessary naval clearance, she became one of the first yachts to visit Calais after the war. Ten years after the evacuation, Thamesa returned to Dunkirk for the first reunion ceremony in 1950.

Thamesa later played a role in popular culture; in 1964, she helped The Beatles avoid crowds by transporting them to Thames Television studios at Teddington on the river. In 1975, she conveyed an anti-VAT petition to Parliament and has appeared in television programmes, including Andrew Marr's History of Britain.

Minnehaha was designed by William McMeek and built by J. S. White's shipyard in Cowes in 1936. The trial report described her with conservative terms such as "obvious restraint," "sound common sense," and noted that "every comfort that is really seamanlike and reasonable is provided," rather than using more complimentary adjectives like "comfortable" or "spacious." Her original owner based her on the Solent and used her for summer cruising.

Douglas Tough’s son, Bob Tough, served as Commodore of the Association of Dunkirk Little Ships from 1986 to 1987, and his son John Tough held the same position from 2008 to 2010, later becoming Honorary Archivist in 2018. Thamesa led the fleet back to Dunkirk for the 2010 Return.