You have to think of Lowcountry river deltas as fast food drive-up windows this time of year, serving up red drum and other fish. That’s likely why Mary Lee just won’t leave.

The 16-foot-long, 3,456-pound great white shark apparently was circling back from Cape Fear, N.C., on Friday, poised to maybe make her third run in about a month through the waters off Charleston-area beaches.

A satellite tracking transmitter attached to the shark pinged twice as she surfaced moving south off Myrtle Beach.

This time of year, the entire continental shelf from North Carolina to Florida is wintering ground for a whole host of sea creatures. Mary Lee might just be sampling the whole menu.

“It’s been an excellent year for red drum. They schooled up early and have been hanging around,” said biologist Bryan Frazier, with the South Carolina Department of Natural Resources.

Mary Lee first showed up off Isle of Palms in early November, and might have nosed into Charleston Harbor.

She caught the attention of surfers after Norman Godfrey, of Ocean Surf Shop on Folly Beach, posted her presence on social media. Since then, her exploits have captured the imagination of people tracking her on the Ocearch monitor website.

Great whites are the “lions of the sea,” apex predators with little to fear in the water. They can grow to longer than 20 feet and weigh nearly three tons.

The sharks were infamously mischaracterized as man eaters in the 1970s book and movie “Jaws.” Humans aren’t part of their diet. Attacks off the West Coast, Africa and Australia have been attributed to the sharks mistaking humans for threats or a prey species. Surfers, for example, are thought to resemble sea lions.

Mary Lee was satellite tagged in New England and named by Ocearch, a group researching great white behavior.

After arriving here in early November, she tracked to Florida, then returned over Thanksgiving weekend, making her way up the Georgia coast delta by delta.

Since then she had been traveling north. Until Friday.