INDIAN OCEAN (Feb. 11, 2021) Aviation Boatswain's Mate (Fuels) 3rd Class Emely Ortega looks through a refractometer to see if the levels of Fuel System Icing Inhibitor (FSII) are within the acceptable range for use on board the Expeditionary Sea Base USS Hershel "Woody" Williams (ESB 4) in the Indian Ocean, Feb. 11, 2021. Hershel Williams is operating in U.S. 6th Fleet to conduct interoperability training and building strategic partnerships with their African partners. (U.S. Navy photo by Mass Communication Specialist 2nd Class Eric Coffer)