Underwater maps of shipwrecks that are produced by underwater archaeologists and/or divers. These maps are used when exploring a wreck underwater and they are very useful as an aid to identification of a wreck and its parts.

aka: BluePrint, SiteArchitecture? A diagrammatic expression of the site's structure to the end-user (i.e., the roadmap that appears on the site). -- DrueMiller? A representation of the organization of a website, usually including links to all the pages on the website. Used to help users find and get to pages on the site and help them build a conceptual understanding of the site structure." -- UsabilityFirst A Site Map is a diagram in which the various pages or page types throughout the site and the user paths to and from them. -- ChristinaWodtke A content object that graphically represents the levels of the site hierarchy. -- KatHagedorn

See Google Sitemaps.