A federal map of Port of Charleston has been updated with more details to help guide larger cargo vessels through the waterway, official said.

The National Oceanic and Atmospheric Administration's new nautical chart provides details like depth and obstructions further east in the harbor, covering an additional 345 square nautical miles missing from the old map, according to NOAA officials.

This is the first update to the local mapping since 1936.

The navigational details are intended to help both recreational boaters and harbor pilots, who are tasked with steering large cargo vessels through the local waters, officials said.

"The creation of this chart directly responds to requests made by Charleston pilots, who bring in larger ships with deeper drafts than they did when we made the original harbor chart in 1936," said Rear Admiral Gerd Glang, director of NOAA's Office of Coast Survey. "This new chart will meet current needs and, even more important, the future needs of maritime commerce in the Port of Charleston."

The new mapping comes as the State Ports Authority is seeking to deepen Charleston Harbor from 45 to 50 feet to accommodate larger cargo vessels from an expanded Panama Canal.

Officials said the previous nautical chart was outdated because previous deepening projects changed the sea buoy and channel entrance over nine nautical miles.

"This gives you more clarity of the water depth as you go to coastal water from truly deep ocean water," said John E. Cameron, executive director of the Charleston Branch Pilots Association.

Cameron added that the new mapping gives more details about the waters at the entrance of the shipping channel, allowing for better navigation of larger vessels.

"Ships are getting deeper and an element of that are the margins are closer to the bottom of the ocean," he said.