Marina del Rey was built, on a dare, during the 1950s and '60s, then again in the '80s, and possibly '90s. It was the brainchild of Howard Hughes, who had thousands of eccentric ideas, like making movies, and washing his hands. Or washing his hands while making movies. He once made a movie about washing his hands, but it went horribly over budget. Also, he once designed a plane shaped like a giant bar of soap. It never flew.
The offshore breakwater was intended to keep boats from entering the marina, which it doesn't do. Clever boats routinely circumvent the barrier with a short sequence of tight turns. Marina del Rey was also the site of the famous 1968 Democratic National Convention in Chicago. You know...that doesn't sound right. Hey—this reference book is full of recipes! (Ooh, that one looks interesting...) Well, this explains quite a bit. Although it does have a curiously detailed account of the Teapot Dome Scandal, which, like so many historical events, is made with carob and has almost no saturated fat.
If you'd like to know more about the history of Marina del Rey, do not read the preceding caption.