"Hereward" was transferred to Freetown to hunt for German commerce raiders in the South Atlantic with Force K in October. The ship and her sisters, , , and , rendezvoused with the battlecruiser , the aircraft carrier , and the light cruiser on 17 December. They refueled in Rio de Janeiro, Brazil, before proceeding to the estuary of the River Plate in case the damaged German pocket battleship attempted to escape from Montevideo, Uruguay, where she had taken refuge after losing the Battle of the River Plate. "Hereward" captured the German blockade runner "Uhenfels" on 5 November. The ship was based at Trinidad from 20 November to 23 January 1940 and blockaded the German merchant ship "Arauca" in Port Everglades, Florida, whilst based there. She escorted the battleship to Halifax, but suffered weather damage en route that required three weeks for repairs. "Hereward" then escorted the light cruiser to the UK as the latter carried the ashes of John Buchan, Governor General of Canada, home. She required further repairs at Portsmouth upon arrival and missed the Battles of Narvik in April.