They are the Island's most beloved bridges. The Big Bridge and the Little Bridge are going to be rebuilt in concrete, if the state has its way.

The two bridges on one of the Island's most scenic routes, along the barrier beach that separates Sengekontacket Pond from Nantucket Sound, will be replaced sometime in the year 2004 and the state is holding a public hearing and is seeking comment on their plan. The hearing will take place Wednesday at 5:30 p.m. in the Megan Alley community room at the Oak Bluffs School. State officials want to talk about replacing the old timber structures with prefabricated concrete. They want to make the bridges better, and they want their work to last at least 50 to 75 years.

The rebuilding of these two structures is no small event in the life of a roadway. These bridges are destinations in themselves for birders, bathers and fishermen. In the summer, youngsters of all ages jump from the Big Bridge into the current below. At night and during the fall, the Big Bridge is one of the Island's premiere fishing spots. Anglers tell stories of large striped bass in residence below. The Big Bridge even achieved a moment of stardom when it was featured in one of the Jaws movies.

The Little Bridge is a destination for kayakers, sailors and those seeking a quieter spot on the Joseph A. Sylvia State Beach. It is the only place on the Island where summer tourists can purchase a hotdog near the shoreline.

Officially the bridges have names commemorating veterans. The Little Bridge is called the VFW Memorial Bridge. The Big Bridge is the American Legion Memorial Bridge.

Bernard (Skip) McCourt, director of District Five with Massachusett Highways, is charged with overseeing the 36 miles of state roads on the Vineyard. Bridges are big part of his business. Mr. McCourt said the replacement of these two bridges and the rebuilding of the Lagoon Pond drawbridge this winter are part of a larger state program to make the state's bridges safe. "Both bridges are deficient, and this is part of a statewide effort to reduce the number of deficient bridges. I'd say these bridges are from fair to poor," he said.

The vulnerable part of the bridge is below the water line. "We have divers down there reviewing bridges every other year," Mr. McCourt said, and both bridges are of serious concern. He said the plan is to make the bridge meet the state standards which would allow them to handle heavier vehicles.

The change from wood to concrete will involve some clearly visible changes. The Big Bridge right now has a 16-timber span. With concrete abutments, Mr. McCourt said: "We will reduce the number of spans down to four. That means more boats can enter and leave. There will be a lot less turbulence and improved flow back and forth." Each concrete abutment, according to the state plan, will have riprap placed in front of it "to supplement existing protection."

The Big Bridge was built in 1932. The Little Bridge was built in 1936. Both were reconstructed in 1953 and again in 1988.

The state's printed plans say that both new bridges will be slightly higher than the current versions. The Little Bridge will be raised by 19 inches and the Big Bridge by 17 inches.

The Little Bridge currently has a 30-foot roadway and a single five-foot sidewalk on its west side. The proposed new bridge would have a roadway 33 feet, six inches wide and a 10-foot sidewalk, adding a total of eight feet, six inches to the width of the structure.

The Big Bridge currently has a 30-foot roadway and two four-foot sidewalks, one on either side. The proposed new bridge would have a slightly narrower roadway of 29 feet, six inches, with a five-foot sidewalk on the Sound side and a 10-foot sidewalk on the pond side. Thus the new structure would be a total of six and a half feet wider than the present bridge.

According to a state release: "The project also includes widening and reconstructing 710 feet of the roadway approaches to the Little Bridge and 300 feet of the approaches to the Big Bridge. These improvements will provide a safer, more reliable structure and roadway for vehicular, pedestrian and bicycle traffic."

Malcolm Reed is the president of the Friends of Sengekontacket, a nonprofit organization committed to maintaining and improving the water quality of the pond. Over the years, the organization has pushed to have the pond dredged and the barrier beach facing Nantucket Sound renourished with beach sand from the pond bottom. The organization is deeply interested in the state's bridge plans.

Mr. Reed said the public hearing process came up rather quickly. "This is all on short notice. We want to know what is going on before we make a decision. We will have a small meeting before the public hearing. We want to listen to what the state has to say."

Mr. McCourt said building with concrete is the most cost-effective route. "It is very difficult for timber to be in that kind of environment," he said. And if the community has any comment on the appearance of the structures, he said: "Those are the kind of comments we are looking for at a public hearing, when it comes to aesthetics."

Mr. McCourt said the 241-foot Big Bridge will be just under 30 feet wide with a five-foot sidewalk on one side and a 10-foot sidewalk on the other side to accommodate its multiple users of motorists, pedestrians and bicyclists.

The 60-foot Little Bridge will be 33 1/2 feet wide on the roadway with one sidewalk 10-feet wide.

"The two bridges will be constructed in two stages in order to maintain traffic," Mr. McCourt said, similar to the building of the Hariph's Creek Bridge, done a few years ago. Mr. McCourt said the construction would be done in the off-season. He said the project will involve drainage improvements and incidental landscaping as necessary. The reconstruction work will also make the pedestrian portions of both bridges handicap-accessible under terms of the Americans with Disabilities Act.

Lawrence J. Cash, the project manager, is expected at the public hearing. Copies of the proposed construction plans are at the Oak Bluffs and Edgartown town halls.