© Alain Werquin

The South China Sea (Chinese name Nanhai, or "South Sea") is an arm of the western Pacific Ocean. It extends from the Taiwan Strait in the north to the tip of the Malay peninsula in the south (Singapore), washing the coasts of China, Vietnam, Malaysia and the Philippines and extending towards Cambodia and Thailand in the Gulf of Thailand. At the tip of the Malay peninsula, it connects with the Andaman Sea and then the Indian Ocean through the Strait of Malacca. The South China Sea forms a special link between China and Continental and Insular South-East Asia ("Indochina" and "Insulindia").

The whole region is subject to the regime of the Asian monsoons (north-west monsoon in winter and south-east monsoon in summer). Indonesia (2,000 km north to south – 5,000 km west to east) is on the equator. The large island of Sumatra (443,065 km²) has an equatorial climate with heavy rainfall throughout the year, while Java (132,000 km²), for example, has a tropical climate, with more abundant rain from November to May.

Part of the Indian Ocean, the Java Sea where the wreck was found is delimited by the southern coast of Kalimantan to the north, Java to the south, Sumatra to the west and Sulawesi to the east. It opens into the South China Sea via the Karimata Strait, around 150 km wide, and into the Celebes Sea via the Makassar Strait. An epeiric sea with a maximum depth 67 metres, it is still very well stocked with fish. The winds, which rarely blow above Force 5, create currents here which generally flow downwind. Visibility is often poor due to fog and dry mists. Local gales are short-lived but can be very violent, especially during the north-west monsoon; the heat storms are frequent but brief and localised. The Java Sea is part of the Indonesian archipelagic waters.