The new nautical chart 11525 extends eastward, to cover an additional pilot boarding area for vessels headed to the Charleston Harbor.

The federal government has released a new nautical chart of Charleston Harbor, the first time the chart has been updated in almost 80 years.

The rare 14th-century portolan chart is worth $7.5 million. Robert Gauthier / Los Angeles Times / Getty Images Last fall, Christie’s auctioned off a “highly unusual” nautical map as part of ...