(NBC) - As darkness fell on the North Carolina coast, Earl strengthened, bringing with it powerful waves, but also uncertainty.
"Earl is a big unknown. If he stays out to sea, we could have gotten rain," vacationer Carol Stauffer said.
Beach house owner Junior Wiseman replied to the question, "Do you board up?" with, "Haven't yet, might be the first."
But officials warned the that the slightest change could bring a direct hit and that either way, hurricane and tropical storm force winds are now less than a day away.
On parts of the Outer Banks, mandatory evacuations are underway…watches and warnings are in effect from North Carolina all the way to New England. A huge stretch of the country is in the strike zone.
"The hurricane is coming and I'm hoping we can make it back into town fairly quickly. I'm a little nervous about roads for evacuation," vacationer Cherry Costa said.
So anxious vacationers packed in their weekend plans and headed to safer ground, while on New York's Long Island marinas hauled boats out of the water.
"The tidal surge is going to be tremendous. They're calling for ten, eleven, twelve feet, that will be above the pilings. If a piling comes down on one of these boats, they'll sink," Henry Uihlein, the owner of Uihlein's Marina said.
Millions now watch to see where Earl will go, the storm already crashing Labor Day weekend plans up and down the coast.