The ferry that has served the Rockaway community in the two years since Superstorm Sandy struck and knocked out its main subway line, will set sail one last time Friday night.

The de Blasio administration is sinking the ferry service, having cited the high cost to the city and relatively low ridership, despite protest from residents who say it is a much needed transit option for the isolated community.

Seven Queens lawmakers -- Borough President Melinda Katz, Assemblyman Phil Goldfeder and Rep. Gregory Meeks among them -- met with Mayor Bill de Blasio to salvage the ferry.

"We are extremely disappointed at the decision to discontinue ferry service to the Rockaways," the elected officials said in a joint statement. "We will continue to fight for a ferry that the Rockaways deserves and need to connect the peninsula to lower Manhattan."

The ferry, operated by Seastreak, got Rockaway residents to Manhattan after the A train was down for seven months following Sandy. The service then complemented the A train, which ferry supporters lament as a long ride to Manhattan with spotty service. The service then went to Brooklyn Army Terminal to help R train riders whose link into Manhattan -- the Montague Tunnel -- had been closed for 14 months until September for Sandy-related repairs.

There will be a rally for the ferry for its last run; it pulls into Rockaway at 8:45 p.m.

Phil McManus of the Queens Public Transit Committee complained that the city did little to promote the service, change the schedule to encourage more riders, or offer a shuttle service to bring people to the ferry.

"We're coming to a point where we have to expand our transit system, including citywide ferry service," McManus said. "We know that the ferry is essential for us."

The city Economic Development Corp., which partnered with Seastreak to operate the ferry, referred a request for comment to City Hall, which instead referred to remarks de Blasio made last week about the need to devise a "vision for the long-term ferry service around the city."