Why in news?
India and Singapore began the 33rd Singapore–India Maritime Bilateral Exercise, or SIMBEX, at Visakhapatnam on 21 October 2026. The exercise brings naval personnel together to practise coordinated operations, rather than merely make a ceremonial port visit. The official programme runs until 26 October, with preparation in harbour followed by training in the Bay of Bengal. For the 23 October edition, the harbour phase is under way; the sea phase is scheduled for 24–26 October. The practical aim is interoperability: helping two national forces understand procedures and act together more effectively. The programme is a training engagement, not a reported combat operation or proof that every planned drill has already succeeded.
A recurring relationship, not a first encounter
The exercise began in 1994 under the name Exercise Lion King. Its repeated editions have given successive groups of sailors opportunities to work with counterparts from the other navy. Singapore's Defence Ministry described the 2025 edition as the longest continuously held bilateral naval exercise India had conducted with another country. That is a specific naval comparison, not a claim about every Indian military engagement. More importantly, repetition allows cooperation to move beyond the arrangements needed for a single visit and build on earlier professional contact.
The previous edition also shows why each year's details need to remain distinct. In 2025, the shore phase took place at Changi Naval Base in Singapore, followed by activity in the southern South China Sea. That edition included ships and aircraft identified in Singapore's account of the completed exercise. Those 2025 participants do not automatically form the 2026 roster. A familiar exercise name provides continuity, but the host, training setting and participating platforms must be identified from the relevant year's programme.
Why preparation in harbour comes first
The 2026 schedule places professional discussions, visits between ships and planning meetings in the harbour phase. These activities help personnel understand how the other navy organises its work before attempting coordinated tasks at sea. Interoperability is not simply owning similar equipment. Consider a general example: a situation report understood aboard one ship may need explanation when passed to a partner. Shared planning helps establish how information, responsibilities and intended movements fit together.
This is also why exchanges between specialists have practical value. A ship contains different professional teams, and successful coordination depends on connections between their tasks. A discussion ashore can clarify a procedure without the additional pressures of a moving vessel or a changing maritime situation. Singapore's account of the 2025 exercise describes simulator training and exchanges on maritime air operations and boarding procedures. That earlier experience illustrates the purpose of preparation; it does not establish that the identical simulator programme was used in Visakhapatnam this year.
The ships have roles as well as names
The Republic of Singapore Navy's ship RSS Supreme arrived on 21 October. India's official account places the opening ceremony aboard INS Nilgiri and INS Kamorta, ships of the Indian Navy. Singapore's navy identifies Supreme as a Formidable-class frigate, a warship designed to deal with threats in more than one dimension. Its published description covers capabilities against surface, airborne and underwater threats. These are the platform's design roles. A specific exercise selects activities within its training programme, rather than necessarily using every capability listed for the class.
Nilgiri is the first frigate of India's Project 17A and was commissioned on 15 January 2025. Commissioning marks a vessel's formal entry into naval service. Participation in a later bilateral exercise is a different event, involving crews, procedures and cooperation rather than the ship's initial induction. The distinction matters when describing capability development. Building a platform and bringing it into service create the basis for operations; repeated training is part of learning how to use platforms together. The SIMBEX announcement does not itself provide a public performance score for any ship.
Why underwater cooperation presents a different problem
The planned sea phase includes anti-submarine warfare, alongside activity concerning surface and airborne threats. Underwater detection has a different physical basis from simply looking across the sea. Sonar, short for Sound Navigation and Ranging, uses sound because it travels effectively through water. An active sonar sends a sound pulse and analyses returning echoes. A passive system listens for sound without sending such a pulse. These are general sensing principles, not a disclosure of the particular sensors or detection results of SIMBEX 2026.
The distinction also explains why detecting a signal is not the same as having a complete picture. A sound's direction, its source and an object's distance are different questions. Passive listening does not automatically provide a direct distance measurement from one observation. In a joint setting, the broader coordination problem is how different participants understand and combine information. Underwater activity therefore involves interpreting information as well as operating equipment. The public opening announcement describes planned training, rather than reporting the detection or engagement of a submarine.
Surface and air activity need a common understanding
Surface warfare concerns threats involving ships and other vessels; air defence addresses threats from above. Coordinating across these areas requires participants to understand intended positions and responsibilities, while keeping track of different information. In a simplified example, a report useful aboard one ship must remain understandable when passed to another. Communication and shared planning therefore connect the ship's individual capabilities with the wider group's task. The exercise programme's breadth reflects that coordination problem, without identifying every technical system that would be involved.
The location connects two maritime settings
Visakhapatnam lies on Andhra Pradesh's eastern coast, facing the Bay of Bengal, with the Eastern Ghats inland. It is also the headquarters of India's Eastern Naval Command. The host location therefore gives the harbour activity a direct connection with India's eastern maritime setting. Singapore lies farther southeast, near the southern end of the Malay Peninsula. The locator map shows that relationship without drawing an assumed route followed by the visiting ship. A port's position is verifiable geographical context; an exact exercise area requires separate operational information.
The nearby Malacca Strait lies between the Malay Peninsula and Sumatra, and connects with the Singapore Strait. This waterway system is important to shipping between the Indian and Pacific oceans. The International Maritime Organization explains that safe navigation and environmental protection there involve cooperation with the coastal states. A bilateral exercise in the Bay of Bengal does not transfer authority over these straits or create a new right to control commercial shipping. Their relevance is the wider maritime relationship, not a claim that SIMBEX is taking place inside them.
Training fits within a wider policy relationship
India and Singapore elevated their relationship to a Comprehensive Strategic Partnership in 2024 and adopted a roadmap in September 2025. Its defence and security section supports regular military exercises, maritime security cooperation and submarine rescue. It also calls for cooperation in maritime domain awareness: building an understanding of relevant activity at sea. The roadmap specifically refers to information-fusion centres and liaison officers. These connect the exercise with an existing policy framework, rather than making the 2026 opening a newly signed defence treaty.
Cooperation is best understood through the particular activity and arrangement involved. An exercise, an information-sharing relationship and a rescue mechanism serve different purposes. None should be treated as an automatic promise of joint military action in every future situation. Equally, the absence of a combat operation does not make training meaningless. Familiarity with counterparts and procedures can support future coordination. Its value has to be demonstrated through the quality of preparation and execution, not inferred solely from the number of ships photographed together.
Conclusion
SIMBEX 2026 carries an established naval relationship into another cycle of practical preparation and planned activity at sea. The immediate sequence is clear: harbour work at Visakhapatnam before the scheduled Bay of Bengal phase. The central task is to connect people, information and different shipboard roles into coordinated action. That is a more specific purpose than a ceremonial display, but it remains a training purpose. As of 23 October, the programme explains what is intended; the later conduct and assessment must establish what was actually achieved.