On Coney Island Boardwalk, Concrete and Plastic Replace Wood Memories, more than wood and nails, have long been embedded in the weathered Boardwalk of Coney Island: a first kiss, a marriage proposal, a roller-coaster ride, a hot dog and a custard cone, a seaside stroll in New York City. But rites of passage take their toll. And one day soon, it seems, economic reality will pave over sentimentality. After a yearlong fight over the city's proposal to use concrete to replace the wooden boards along stretches of the aging, 2.7-mile Boardwalk, the city's parks department has offered a compromise of sorts - but wood is not part of the plan. Instead, the department has promised to use a combination of concrete and a type of recycled plastic that looks like wood. They want a 12-foot concrete section for emergency vehicles, with 19-foot-wide sections of the plastic polymer on either side for pedestrians. This is not the all-concrete sacrilege that local preservationists had feared, but they still see the hybrid product as a travesty of tradition - not to mention a worrisome indicator of what could happen when the city decides to renovate other portions of the fabled walkway. "It's like putting a piece of plastic into a diamond ring, and this is our jewel," said Rob Burstein, 57, the chairman of the Coney-Brighton Boardwalk Alliance, whose online petition to keep the Boardwalk wood was signed by more than 1,700 people in the past year. The five-block stretch in question is in Brighton Beach, a mile from the heavily-traveled historic district of Coney Island, where wood is still used. Mr. Burstein, who lives in Brighton Beach, was offended that his neighborhood could not have wood. "What are we, chopped liver?" he said. Two small sections of the Boardwalk are already concrete. The push for new materials followed a campaign by environmental advocates and a directive from Mayor Michael R. Bloomberg to reduce the use of tropical hardwoods from endangered rain-forest supplies. The parks department's plan must be approved by the Public Design Commission, whose members are appointed by Mr. Bloomberg. If the commission approves the plan, as it is expected to do, reconstructing the Boardwalk would take at least another year, said Adrian Benepe, the parks commissioner. Some commission members said they would reluctantly embrace the synthetic wood-concrete compromise. "I have pushed them to look at every possible wood alternative, and they have persuaded me that there aren't wood alternatives that are practical," said one commission member, Otis Pratt Pearsall, a trustee of the Brooklyn Museum. With that in mind, he said he would support the hybrid plan because "it is important to have the thing look as Boardwalk-y as possible." Another commissioner, Paula Scher, shared that sense of resignation. "If you think we're happy that wood is being replaced by material we find less appealing, that is certainly not the case," said Ms. Scher, a partner at Pentagram Design. It's called a Boardwalk, and if you use other material, it loses its identity. I understand that, but it's so much better to have a surface to walk on next to the beach. "We love our icons of the past, and sometimes you can preserve them," Ms. Scher said, but "things have changed." Mr. Benepe said the parks department had investigated every option, from natural woods like Douglas fir and black locust to treated woods like Southern yellow pine. They concluded that such hardwoods were neither durable enough nor, in the case of black locust, abundantly available. Opponents rejected this argument, and Michael Caruso, a forestry expert in West Virginia, said that black locust wood could be ordered in sufficient quantities. The plastic composite, which can last 75 years, is cheaper than wood to build with and maintain, Mr. Benepe said. According to City Council member Domenic M. Recchia Jr., it costs more than $1 million a year to maintain the wooden Boardwalk. Under the hybrid plan, it would cost the city $6.85 million to replace the 60,110-square-foot stretch of the Boardwalk from Coney Island Avenue to Brighton 15th Street. That is more expensive than concrete, but cheaper than some natural woods that could last just eight years, the parks department said. "Given all the variables, this addresses as many of the desires as possible," Mr. Benepe said. The local community board, which has an advisory role, rejected the plan for synthetic wood last spring. One board member, Todd Dobrin, who founded a group called Friends of the Boardwalk, said the department was "disregarding the will of the public." Mr. Dobrin said it would be problematic to use concrete in any form. This winter, he said, the concrete sections have been dangerously icy, with poor drainage and numerous cracks. "When you come to the Boardwalk, it's such a peaceful realm," said Soul Bryan, 48, who, like many local residents, takes a round-trip walk on the Boardwalk daily. As soon as you go off the wood, it takes you out of your zone. But Mr. Benepe said he did not believe that keeping the Boardwalk wood was historically important. "Suggesting that you can only have wooden Boardwalks because that's what they were originally built of is like saying you should only have cobblestone streets," he said. Still, economic sense clashes with the emotional connection that many Brooklynites have to the Boardwalk. Dan Klores, a public relations executive and filmmaker from Brooklyn, remembered running on the Boardwalk in the 1970s and encountering Abraham D. Beame, who was campaigning for mayor. The wooden boards were in disrepair then, Mr. Klores said, and Mr. Beame told the crowd that replacement wood was on order from Honduras. One elderly man, Mr. Klores recalled, did not miss a beat. "Honduras, shmonduras!" the man shouted. We want the wood.