Nagapasa-class (Chang Bogo variant)

The Nagapasa class represents an upgraded iteration of the Jang Bogo design, specifically developed as an improved variant to modernize underwater naval assets. The procurement process began in late 2011 to secure a more advanced capability than existing refurbished Type 209/1300 vessels. While initial proposals considered the acquisition of existing in-service hulls, the program transitioned to the construction of new units. The class is divided into two distinct production batches; the first batch is fully commissioned, while a second batch remains in the early development phase. The designation is derived from a mythical serpent weapon, reflecting its role as a specialized attack platform.

As an attack submarine, the Nagapasa class is engineered for underwater combat and surveillance. The platform utilizes a suite of electronic and acoustic sensors, including active and passive sonar systems, flank sonar arrays, and low-probability of intercept radar for tactical awareness. Navigation and platform management are handled through integrated digital systems, tactical interfaces, and inertial navigation technology. For offensive operations, the vessel is equipped with torpedo tubes configured for heavy-weight torpedoes and guided missiles. Defensive measures include acoustic torpedo countermeasures and periscope systems for reconnaissance.

The Indonesian Navy currently operates three active units of this class. The lead vessel was commissioned in 2017 and assigned to the Eastern Command, while subsequent units entered service between 2018 and 2021. These later additions are attached to the 2nd Fleet Command based in Surabaya. One unit in the class marks a shift in production, representing the first instance of a submarine being assembled at a domestic naval facility. The deployment of these vessels provides the fleet with a sustained presence, supported by an endurance profile suitable for extended operations.