America's most populous state borders the Pacific. Could you clarify further?

The Pacific coastline is very, very different from that of the Atlantic East Coast. For huge swaths, it's very steep terrain that plunges directly into the ocean with fewer natural harbors and shallows to take advantage of for navigation... and many hazards to them.

Areas with natural access to the sea are very built-up along the West Coast. San Diego, Long Beach, Los Angeles, Santa Barbara, Monterey, Santa Cruz, San Francisco... along with many smaller port towns. There's just a lot of coastline not conducive to navigation, and not a lot of incentive otherwise to build. There's not much there, there.