1971 Map of Chesapeake Channel

About this map

The Chesapeake Bay Bridge-Tunnel dominates this 1971 planimetric study, slicing diagonally across the underwater topography of the lower bay. This specialized bathymetric sheet, updated with National Ocean Service data in 1986, details the complex seafloor environment where the Chesapeake Channel and North Channel provide passage through shifting shoals. The transition from bridge to tunnel sections is clearly marked as the structure crosses the deep water of the primary shipping lane. Shallow hazards such as Nine Foot Shoal, Inner Middle Ground, and the broader Middle Ground bank are mapped with precise meter contours. These features illustrate the engineering challenges involved in spanning the Chesapeake Bay, where man-made infrastructure must navigate the natural troughs and rises of the estuary floor.