The Republic of Singapore Navy (RSN), Indian Navy and the Royal Thai Navy are participating in the inaugural Singapore-India-Thailand Maritime Exercise (SITMEX) from 16 to 20 September 2019. The exercise was announced by Indian Prime Minister Narendra Modi in his Keynote Address at the 14th Shangri-La Dialogue in June 2018. Hosted by India, the exercise comprises a shore phase held at Port Blair, and a sea phase in the Andaman Sea.

The RSN is participating with the Formidable-class frigate, RSS Tenacious. The exercise involves five ships from the three navies and more than 500 exercise participants. During the shore phase, the participants will engage in exercise planning and professional exchanges. Thereafter, the navies will conduct manoeuvring, navigation and gunnery drills, as well as boarding operations, in the Andaman Sea.

At the opening ceremony, Commanding Officer of RSS Tenacious Lieutenant Colonel Michael Chan said that "the exercise underscores the shared responsibility of countries to work together to keep sea lines of communication open, and strengthens interoperability between the three navies." The exercise also reaffirms the long-standing defence relationships among Singapore, India and Thailand.