Rising sea level changes, together with changing geology, may be preventing the breach at Norton Point Beach from closing, according to a National Oceanic and Atmospheric Administration oceanographer.

Todd Ehret, an oceanographer with the National Ocean Service in Maryland, said he is aware of Edgartown’s problem. He said there is no assurance that the opening at Norton Point Beach will close, though history suggests it.

When it comes to sandy beaches, barrier beaches and inlets, Mr. Ehret said changes are under way around the country.

“The environment we live in is in a world of change,” he said. “These features may linger for 10 years, they may be a permanent feature.”

The gap at Norton Point Beach, initially opened by a storm in April of 2007, is wider than anyone can recall. Currents running through Edgartown harbor have grown stronger in just the past several months and there is no evidence that boating in the harbor will get easier.

There is even a small island in the middle of the opening which has survived since last winter and it has earned the name Charlie’s Island, named after the town harbor master, Charlie Blair.

Though the opening is more than a year old, it has done the opposite of what history suggests. Instead of getting smaller and moving eastward, the opening has grown wider and more water is flowing through it.

“There is a river running through Edgartown,” said William Roman, manager of the Edgartown Yacht Club.

Every few hours, the river changes direction. Instead of Edgartown having one opening to the sea, it now has two openings. Currents can be rising from two directions, or falling when the current is moving either direction. The yacht club’s mariners have had to adjust.

Mr. Blair estimates that since last summer, the speed of the current running between Memorial Wharf and Chappaquiddick Point has increased 25 per cent.

“That is significant. I’d say it is moving five knots,” Mr. Blair said. He said the incidence of boats banging into the gas dock at North Wharf is up. “People aren’t used to this current. They are unprepared.”

Since last year, the town moved the water barge from off North Wharf into the inner harbor off Collins beach in an effort to cope, to find a place out of the current where boaters can come and get free water, a service offered by the town.

Mr. Blair’s message to boaters this summer is the same as last summer, with a little more emphasis: use extreme caution when operating a boat in areas where the current is running strongest. Watch out for eddies, places where in a small area the current is running in two directions.

The effects of the changing tides are rippling beyond the harbor.

Robert Eldridge (Ridge) White Jr., publisher with his wife Linda, of the Eldridge Tide and Pilot Book, a much-respected nautical Bible, made calls to the Gazette last week searching for new information on the tide and currents in the harbor, in advance of publication of their 2009 edition —the 135th anniversary issue.

Mr. White said he is interested in updating the book to reflect the change in high and low tide in the harbor if anyone has numbers.

The National Oceanic and Atmospheric Administration, which provides the data for tides and currents, has no new data and has no immediate plan to help. The Eldridge book is written based on federal data on tides.

Mr. White said: “We’ve had a handful of inquiries. People are hoping we have the answers. Unfortunately, we have to wait for NOAA or some other local source.”

The problem of changing currents and outdated NOAA information isn’t unique to Edgartown. Mr. White said the problem stretches all around the country.

“There are many places up and down the coast that have problems,” he said. “What is disturbing is the funding for NOAA. It is lower than it has been in a long time. In some cases they have determined that much of their data is more than 60 years old, not reliable. Given the lack of funds they are unable to generate new data.

“NOAA has delisted a number of harbors because of unreliable old data,” Mr. White said. “They are Camden, Me., Manchester, Marblehead, Edgartown, Vineyard Haven, Menemsha, Padanaram and Stonington, Conn. The list goes on.

“We at Eldridge are meeting the challenge by either delisting those ports or by inserting an asterick, calling the reader’s attention to the issue,” he said. “Given that there is no other information, we feel running old information is better than no information.”

There is plenty of local interest in trying to figure out what the tides are now in Edgartown harbor.

Chris Kennedy, Islands regional director for the Trustees of Reservations, said he assigned summer staff to initiate some form of recordkeeping that might help determine when high tide and low tide take place.

“We tried. We have not come up with a reliable formula to tell us when the current is slowing to the north or when it is slowing to the south,” Mr. Kennedy said. “We know that typically tides should change in any given place every six hours. But that is not the case here. The tides do not shift to any observable pattern, as one would expect for instance with Cape Pogue. We can easily predict high and low tide for West Chop, East Chop and Cape Pogue and Wasque.”

Peter Wells runs the Chappaquiddick ferry service and he doesn’t know either. All he knows is that the current is costing him more money in fuel and time. He concurs with the harbor master that the current is up to five knots when last year it was about four.

Bigger motors have been installed in both of the Chappaquiddick ferries. They now have 225 horsepower diesel engines. Prior to the opening, they were less than 200 horsepower.

“The trip is longer. It used to take 55 seconds to cross the channel. Now it is always more than a minute and a half and sometimes it takes 2 1/2 minutes to cross,” Mr. Wells said.

He said the impact of the increased current also has changed the bathing beach area at Chappy Point. He said those who used to be able to watch the fireworks from Chappaquiddick Point are going to find their beach has eroded away. “There is no place where people can sit on the beach,” he said.

At the Edgartown Yacht Club, where boats come and go all the time, the talk is about the changing currents and tides.

Mr. Roman said: “You look out there and the current is moving right along. There are a couple of mooring balls at the Narrows that are underwater when the current is moving strongest, especially when the currents are ebbing.”

To make it from one day to the next, Mr. Roman said he uses his own formula for the tide. “What I see is the tide turns an hour and a half earlier than the traditional times for Edgartown Harbor. That is loosely close to the tide for Wasque,” Mr. Roman said.

Partly because of the stronger tides, the club is looking to relocate its junior yacht club to a place outside of the harbor.

The club has signed a purchase-and-sale agreement with Eric and Michael Zizza to purchase an acre and a half of waterfront property north of the Chappaquiddick Beach Club. The purchase is contingent on the club getting the necessary permits.

The club now stores the youth program’s little sailboats on floats in the inner harbor near the shore of the Chappaquiddick town owned Gardner property. Mr. Roman said it takes quite a lot of time to get the sailors and their boats to the outer harbor where they can compete.

Moving the fleet to the outer harbor, Mr. Roman said, would “contribute to the quality and safety of the program.”

If the club were to acquire the property, the boats would most likely be stored on the beach and not on floats. If the permit process and the purchases go smoothly, the club will start using the property next year.

“We wanted to move the junior club prior to the opening. But this certainly has gotten our attention,” Mr. Roman said. “This will get the sailors significantly closer to the sailing area.”

Mr. Roman said stronger current in the harbor has put a strain on boaters using the harbor.

“I saw a Herreshoff sailing backwards,” Mr. Roman said.

This summer the club will host plenty of sailing events and there is talk about ways to make sure the boaters get where they want to go amid the 5-knot current that changes direction in the span of a few hours. There is talk of towing the boats in a long chain.

“Even the powerboats have trouble. The current will push you sideways and get you into an odd position, especially the smaller outboards,” Mr. Roman said.

Jeffrey Ferguson, the chief of the hydrographic survey division with NOAA, reports the agency is working on a survey in Vineyard Sound that is taking several years to complete.

For close to a decade, NOAA has been surveying the navigable waters of Vineyard Sound and the navigable waters extending into Buzzards Bay for future charts. The 208-foot NOAA vessel Thomas Jefferson will be in Vineyard waters in mid-July as part of that project.

“We are surveying 100 square miles,” Mr. Ferguson said. The area is at least the size of the Vineyard.

But the survey area doesn’t include Edgartown harbor.

Mr. Ehret, an oceanographer for NOAA at Silver Springs, Md., said the Norton Point opening poses a familiar problem.

“Our office is responsible for tide and currents and analysis for the entire United States coastline, from Maine to Texas and Alaska, southern California and the Pacific Islands.

On the subject of Norton Point Beach opening and a need for new tidal data, Mr. Ehret said: “We do run into these types of problems. We are dealing with the entire coastline on a national scale. Sometimes the little, very small issues get overlooked.”

However he said, there is another problem with issues like the Norton Point Beach opening.

“Unfortunately, looking at the history, the opening does fill back in,” he said. “The hole moves. Whenever the opening moves, it changes the dynamic. As the opening moves from one side to the other, the tides and currents are going to continually change until it gets back to a more stable system.

“The only real remedy is to have new data collected in that area. But if the dynamic changes, that data will be worthless,” Mr. Ehret said.

“This could all be a symptom of greater global sea level changes,” he said. “The environment we live in is in constant change. This may be transitory.”

Mr. Kennedy said that the opening at Norton Point Beach is changing a lot more than just the inner harbor waters. It is changing South Beach.

“Remember the Bunker?” Mr. Kennedy asked.

The Bunker at South Beach, which used to be above water for many years and was built for military purposes during World War II, is now located offshore because the beach has receded. It is about halfway between the Left and Right Fork.

“The currents have changed,” he said. “We suspect that the currents are now scouring the bottom sediments around the old Bunker, which in turn is uncovering additional munitions all along the shore down to Wasque. We are finding munitions at a rate of one every six to eight weeks.”