The Ptolemy Map, created by the Greek geographer Claudius Ptolemy in the 2nd century CE, is considered the oldest known map of India.

The Gnomonic Projection is not a type of map projection but a method of representing the Earth's surface on a plane.

The Somali Current is a strong seasonal current that flows along the western coast of India during the summer monsoon.

Surat is not a major port city in India, although it is an important industrial and commercial center.

The Java Trench, located south of Java, Indonesia, is the deepest point in the Indian Ocean, with a depth of approximately 7,450 meters.

Patch Reef is not a type of coral reef. It refers to a small, isolated coral reef that is typically found in deeper waters.

Great Nicobar Island is the largest island in the Andaman and Nicobar Islands, located in the Bay of Bengal.

Ramsar Site is not a type of marine protected area in India. It refers to a wetland of international importance designated under the Ramsar Convention.

Maitri is the name of the Indian research station located in Antarctica.

The Kuroshio Current is a major ocean current in the Pacific Ocean, not in the Indian Ocean.

The Gulf of Mannar Coral Reef is the largest coral reef in India, located in the Gulf of Mannar between India and Sri Lanka.

Salmon is not a type of marine fish commonly found in Indian waters.

INS Sagardhwani is the name of the Indian oceanographic research vessel.

Manatee is not a type of marine mammal commonly found in Indian waters.

The National Institute of Oceanography is the Indian organization responsible for oceanographic research.