The Pacific Ocean and the Indian Ocean meet at the southeastern coast of the Indian subcontinent, near the island of Sumatra, and extend down to the waters off Western Australia. A notable point of their confluence is the southern tip of the Indian Peninsula at Cape Comorin (Kanyakumari), India, where the waters of the Bay of Bengal (part of the Indian Ocean) and the Arabian Sea (also part of the Indian Ocean) meet.
However, a more recognized point where the distinct waters of these oceans meet but do not mix is at the confluence near Indonesia, around the Sunda Strait and the waters around Java and Sumatra.
The phenomenon where ocean waters meet but do not immediately mix is due to differences in water properties such as salinity, temperature, and density.
These differences create a visible boundary between the water masses, known as a halocline, thermocline, or pycnocline, depending on which property is causing the separation. The distinct separation is temporary and eventually, the waters do mix over a longer period due to currents and diffusion.