SMS Hertha was a Victoria Louise-class protected cruiser (not a battleship) of the Kaiserliche Marine, launched in 1897 and commissioned in 1898.  By 1913 she was serving as a cadet training ship.  During a seven-month Atlantic training cruise (mid-August 1913 to mid-March 1914), she was ordered to Veracruz to protect German nationals and economic interests during the Mexican Revolution.  She remained in port from 21 October to 2 November 1913, then continued to the Antilles before returning to Kiel on 13 March 1914. 

The photograph was taken shortly after Victoriano Huerta consolidated power following the February 1913 coup against Madero, and roughly four to five months before the Tampico Affair of April 1914 — which is when Hertha was recalled to reinforce SMS Dresden off the Mexican coast. This dating is confirmed by Wikipedia, which gives the same window.

Reference/Source: Some information furnished by BRAVE AI.