This is a map of Jamacia. It is an island in the West Indies that was discovered by Christopher Columbus on May 4, 1494. It is the third largest island in the Caribbean Sea. It is slightly larger than the island of Hawaii. Jamacia is an independent island within the Commonwealth.The capital and largest city of Jamacia is Kingston. This island has few large rivers, and only the Black River is navigable. The population consists mostly of African Blacks. The people are concentrated on the coastal plains; the highland are mostly uninhabited. On the coast, the average annual temperature is about 80o F. In the moutainous regions, the average annual rainfall is 77 in., but it can reach 200in.