The Intracoastal Canal

The History Channel last night presented an interesting and informative program regarding the Intracoastal Canal. I have always been aware of the Intracoastal Canal or Intracoastal Waterway, but never fully realized how important and complex it is. Following the program I googled on some additional information. I was hoping I could find a way to ask a question about the Canal. The waterway consists of an Atlantic coastal canal (Boston to Key West) and a gulf canal (Key West to Brownsville, Texas). My question is: Why is there no Pacific Intracoastal Canal? Such as from San Diego to Seattle?