31" x 41.5" copper engraved chart in Fine condition. A 1" acid burn at center left but not offensive. A US Coast survey of the Entrance to San Francisco Bay. A master sheet issue, being an academic / maritime offering on heavy stock , without fold lines. This being the 2nd edition of the SF Bay Entrance , which included the 1st edition of the Land fall views of the shorelines displayed along the bottom of the chart, an essential tool for dead reckoning . Micro-printed with a surprisingly comprehensive topographic and structure survey of both San Francisco and Oakland / Alameda / San Antonio Creek area