The ocean that borders the United States to the west is the Pacific Ocean. It is the largest and deepest ocean in the world, stretching from the west coast of North America across to Asia and Australia. The Pacific Ocean influences the climate, weather patterns, and ecosystems along the U.S. west coast. It plays a vital role in trade and transportation, as many ports along the Pacific allow the movement of goods and resources. The ocean is also rich in marine biodiversity, making it an essential area for ecological study and conservation efforts.