AbstrakLetak geografis wilayah kerja Lantamal IV/TPI yang sangat strategis, karena terdapat Selat Malaka dan Selat Singapura yang merupakan Sea Lines of Trade (SLOT), Sea Lines of Communication (SLOC), dan choke points untuk jalur pelayaran internasional. Selat Singapura merupakan kawasan perbatasan laut RI - Singapura yang memiliki nilai strategis dan terdapat kawasan Outside Port Limits (OPL) atau yang biasa dikenal dengan kawasan Ship to Ship (STS), Traffic Sparation Scheme (TSS), keduanya berada di Selat Singapura dan Perairan kepulauan dan Zona Tambahan. Selat Singapura merupakan jalur laut di kawasan Asia Tenggara dan salah satu jalur laut yang dilalui ribuan kapal dari berbagai negara setiap tahunnya. Hal ini berdampak pada meningkatnya kejahatan transnasional. Meningkatnya jumlah tindak pidana yang terjadi di kawasan perbatasan RI-Singapura menimbulkan ancaman yang dapat mengganggu keamanan negara Indonesia. Tim Lantamal IV/TPI Fleet One Quick Response (F1QR) di bawah komando Danlantamal IV/TPI berhasil menggagalkan dan menangkap beberapa tindak pidana yang terjadi di Selat Malaka dan Selat Singapura. Kerjasama Lantamal IV/TPI dengan penegak hukum dari instansi manapun yang melakukan patroli di perbatasan laut RI-Singapura antara lain: PSDKP, Imigrasi, Polri, Bakamla RI, TNI AL, KPLP, Bea Cukai, sehingga bahwa mereka mampu melaksanakan tugas penegakan hukum dalam mendukung keamanan nasional.Kata Kunci: Selat Singapura, perbatasan laut, Lantamal IV/TPI, Kerja sama antar Aparat Penegak Hukum, Keamanan Nasional.AbstractThe geographical location of the working area of Lantamal IV/TPI Main Base is very strategic, because there are the Malacca Strait and the Singapore Strait which are sea lines of trade (SLOT), sea lines of communication (SLOC), and chokepoints for international shipping. The Singapore Strait is a maritime border area of RI - Singapore, which has a strategic value, there is also an Outside Port Limits (OPL) area or commonly known as the Ship to Ship (STS) area, Traffic Separation Scheme(TSS), both of which are located in Malacca Strait and archipelago Waters and Additional Zone. Singapura strait namely the sea route in the Southeast Asia region and is one of the sea routes that thousands of ships pass from various countries every year. This has an impact on the increase in transnational crime. The increasing number of criminal acts that occur in the RI-Singapore border area poses a threat that can disrupt the security of the Indonesian state. Lantamal IV/TPI Fleet One Quick Response (F1QR) Team managed to thwart and arrest several criminal acts that occurred in the Malacca Strait and the Singapore Strait. Lantamal IV/TPI cooperation with law enforcers from any agencies that carry out patrols at the RI-Singapore sea border include: Ministry of Marine Affairs and Fisheries, Immigration, Police, Indonesian Cost Guard, Indonesian Navy, ministry of maritime transportation, Customs, so that they are able to carry out law enforcement duties in supporting national security.Keyword: Singapore Strait, the sea border, Lantamal IV/TPI, Cooperation with law enforcers, national security.