After visiting Madeira and Jamaica, the ship arrived in Veracruz, Mexico, on 9 February to relieve her sister ship, , and protect British interests during the ongoing Mexican Revolution. Two weeks later, she visited Galveston, Texas, before heading for Tampico, Mexico where she arrived on 11 March. "Essex" only spent a few days there before returning to Veracruz on 13 March. She was in Tampico when Mexican soldiers briefly detained American sailors buying gasoline for their ship on 9 April (the Tampico Affair) and returned to Veracruz ten days later, two days before the Americans began landing there on 21 April. They were not satisfied by the Mexican apologies and U.S. President Woodrow Wilson ordered the city occupied in retribution and to forestall a major arms delivery to Victoriano Huerta's forces. The Mexicans resisted and stray bullets hit "Essex" the next day, wounding one man who was shot in both feet. Tweedie, escorted by two ratings, was sent to take dispatches for the British Minister in Mexico City on the 26th and returned two days later. Rear-Admiral Christopher Craddock inspected the ship and her crew on 5–6 May. "Essex" sailed for Tampico on 10 May before leaving Mexican waters on the 14th. A month later, the ship was in Quebec City when she was visited by the Canadian Minister of Marine and Fisheries on 16 June. The following month, "Essex" ferried the Governor General of Canada, Prince Arthur, Duke of Connaught and Strathearn, to Newfoundland and Labrador before returning to Quebec City on 20 July.