A buoy off the North Carolina coast recorded waves almost 30 feet (9 meters) high as Florence churned toward shore.
According to Storyful, the video was shot at the Fish Heads Bar & Grill pier in Nags Head.
Parts of North and SC are expecting "catastrophic flooding" due to Florence, despite it only being a Category 1 storm.
It was forecast to make landfall mid-day Friday near Cape Fear, North Carolina, bringing up to 40 inches (1 meter) of rain, and storm surges as high as 13 feet (4 meters), the NHC said.
Storm surges are caused when huge volumes of water are pushed by hurricane-force winds. "This may be worse than what we've seen before", Assistant Fire Chief Joey Roberts said during a press conference Wednesday.
It's been an especially active start to the Atlantic hurricane season, as parts of North and SC are now bracing for impact from a major Category 3 Storm. And although the storm's wind speeds have decreased slightly, says NOAA, the size of the wind field has increased, putting more people at risk.
The National Hurricane Center's best guess was that Florence would blow ashore as early as Friday afternoon around the North Carolina-South Carolina line, then push its rainy way westward with a potential for catastrophic inland flooding.
As Florence drew near, U.S. President Donald Trump tweeted that FEMA and first responders are "supplied and ready", and he disputed the official conclusion that almost 3,000 people died in Puerto Rico, claiming the figure was a Democratic plot to make him look bad.
Gillikin says the North Carolina Coastal Reserve stands ready to respond with whatever resources they can to help any animal suffering after the storm.
Over 1,400 flights have been cancelled, according to FlightAware.com, as most of the coastal region's airports are closed to ride out the storm.