WASHINGTON — All along the Eastern Seaboard, hopes for a new maritime-based economic boom are high. Less than three years from now, the Panama Canal is scheduled to open up a new channel that will accommodate ships carrying double the cargo of those that can currently fit through the canal. Bigger ships, the thinking goes, means bigger business for the nation’s Atlantic ports.

To prepare, New York and New Jersey plan to elevate a bridge that, as it stands now, would block taller container ships. Georgia’s governor proposed selling nearly $47 million in bonds to deepen Savannah’s harbor. Baltimore is finishing work on a bigger berth and larger cranes to offload the next class of “post-Panamax” vessels.

“It’s a virtual arms race in the port industry,” said Allison Skipper, a spokeswoman for South Carolina’s Port of Charleston, which is hoping to make up ground it recently ceded to Savannah, its rival in Georgia. Charleston’s deeper harbor, South Carolina officials hope, will put it in a better spot to attract the bigger boats.

South Carolina Gov. Nikki Haley told lawmakers last month that she wanted to create an infrastructure fund to help pay for further deepening in their state. Federal engineers estimate that dredging a 50-foot channel in the Charleston harbor would cost $300 million. That is a hefty price, but Skipper says it is half the cost of digging out Savannah’s shallower port.

The enthusiasm on the East Coast, though, has not won over skeptics who doubt that the Panama Canal expansion will result in a real economic sea change. From their standpoint, the biggest change of all – a major shift to rely less on West Coast ports and more on East Coast ports – has already happened.

Today, Norfolk, Va., is the only East Coast port that could handle the fully laden vessels that soon might sail through Panama. A few Atlantic ports have handled the larger vessels, which arrive from Europe or through the Suez Canal, but only by waiting for the right tides or by servicing ships that are not fully loaded.

New York, Baltimore and Miami are the next in line with improvements that will let them unload fully loaded vessels from the new class of megaships. But it could take years. The process of deepening a harbor depends on numerous approvals from the U.S. Army Corps of Engineers before dredging can even begin. And federal approval is no guarantee of quick action. For example, work on deepening the Port of Miami, which secured a federal blessing for dredging, is now on hold because of litigation over the project’s potential environmental impact.

In the New York area, it is the height of the new ships, rather than their depth, that poses a major problem. Right now, an 80-year-old bridge between Staten Island and New Jersey has such a low clearance that container ships on their way to Newark or Elizabeth sometimes have to wait for low tide before they can pass under.

Things would only get worse when ships with containers stacked nine high, rather than the current six, start coming through the Panama Canal. The Port Authority of New York and New Jersey wants to solve that problem by raising the roadway on the Bayonne Bridge by some six stories, which would give ships a clearance of 215 feet, but this work would not be completed until long after the bigger ships can traverse the Panama Canal.

“These are not things that happen in a couple months,” said Sujit CanagaRetna of the Council of State Governments. “In a way, we are coming to the party late. But it’s better late than never. Policymakers in all these states realize it’s critical for the continued expansion of the economy.”

Port consultant John Martin says the idea that the Panama Canal will instantly bring more business to the Eastern Seaboard is an “urban myth.” Whatever business the Atlantic ports could easily take from Los Angeles and other Pacific cities has already moved east, he says.

A 10-day labor lockout on the West Coast nearly a decade ago forced shippers to reconsider their heavy reliance on the Pacific ports. Since then, the haulers increasingly have sent more business east, especially when it comes to cargo destined for or produced by East Coast markets. Because of this, a sizable increase in Eastern port business has already happened. The competition is now over goods going to or arriving from the interior. West Coast ports and the railroads that serve them doubt the Panama Canal expansion will siphon off that business.

“Time-sensitive cargo will typically flow through the West Coast ports, which have the infrastructure and technology to process and disperse freight via rail with elevated efficiency, and that doesn’t look like it will change,” said Aaron Hunt, a spokesman for Union Pacific railroad.

Krista York-Woolley, a spokeswoman for the BNSF railroad system, echoes that sentiment. She says the larger canal is a “positive step toward enhancing world trade” but it would not, on its own, move trade eastward.

Regardless, Eastern ports have a lot at stake with their expansion plans. They may not gain as much business as they hope, but without deeper harbors and cranes that can service bigger ships, they will lose future business. Shippers are using bigger and bigger vessels, and ports that cannot handle the larger craft risk being relegated to second-tier status.

The shipping industry may be moving toward a system where increasingly large ships service a decreasing number of ports, CanagaRetna says. That would mean that East Coast ports would be serviced from a hub somewhere in the Caribbean on “feeder” routes.

Whether large ships stop in the Caribbean first or head straight to the United States, the contest among the Eastern ports is about which ones will be the first American ports of call for the new vessels. It is those first destinations that get the most cargo and the most economic benefit.