China and Russia launched the full maritime phase of their Joint Sea-2025 naval exercises on 3 August, sending a combined flotilla from a military port toward waters off Vladivostok. According to the Chinese Defence Ministry, the drills will run through 5 August in the Sea of Japan and at Pacific Fleet training grounds, featuring multi-domain operations involving surface ships, aircraft and coastal forces. The exercises follow an opening ceremony in Vladivostok and deepen bilateral military coordination that has expanded in recent years. While neither side disclosed the exact number of assets involved, Russian media said Pacific Fleet units will join People’s Liberation Army Navy vessels in anti-submarine, air-defence and search-and-rescue practice. Separately, Beijing said it carried out routine patrols in the South China Sea on 3–4 August and, from 1–4 August, the China Coast Guard warned off a Japanese fishing vessel it accused of entering waters around the disputed Diaoyu Islands. The overlapping operations underscore China’s heightened naval activity across multiple theatres.