California's State Parks: California's state park system is one of the country's largest and most successful. Unfortunately, the system remains drastically underfunded and at risk of deterioration—a result of more than $1 billion in deferred maintenance.
What does this have to do with the sea? California's Underwater Parks site explains. Not only an outline of the rich marine and cultural resources within the state's park system, with links to California's underwater parks, the site includes links to articles on California's maritime heritage that are thorough, well-written, and make wonderful reading. The expected is covered, with essays on shipwrecks and historic vessels, but the unexpected also surprises: scroll down to find the article about the airplane.
And keep in mind when you're following the links that these are some of the resources on the endangered list.