Citywide Ferry service will set sail on May 1 along a Rockaway route, Mayor Bill de Blasio announced — and one elected official is calling for naming a boat after the late Det. Steven McDonald.

The other two routes included in the first phase of service, the South Brooklyn and Astoria, will launch on July 1 and in August, respectively. The first route goes from The Rockaways to Brooklyn Army Terminal and then Pier 11 at Wall Street.

“Rockaway residents have some of the longest commute times in the city. We promised we’d bring them our new NYC Ferry service first, and [Thursay, April 7] we’re delivering on that promise,” Mayor Bill de Blasio said in a statement.

Fares will cost $2.75, the going rate of a MetroCard swipe — although Citywide Ferry’s fare payment system is not integrated with the MTA’s, meaning that riders won’t get free transfers onto subways or buses.

Service, operated by Hornblowerand overseen by the city’s Economic Development Corporation, will run primarily during peak commuting hours. Boats can carry 150 people each and will be equipped with Wi-Fi and concessions, including alcoholic beverages. All docks and vessels will be handicapped-accessible.

City second-graders are coming up with names for some of the 20 vessels being built for the service — early contenders include Lunchbox and Friendship Express.

New York City Public Advocate Letitia James, in a March 13 letter to de Blasio, asked the city to name one of the first ferries for McDonald, who was paralyzed after being shot by a teenager in Central Park in July 1986. McDonald, an active member of the NYPD until he died in January at age 59, had been a symbol of strength for the city.

McDonald’s life was “an inspiration to many New Yorkers who were drawn to his inspiring message of forgiveness and perseverance in the face of adversity,” James wrote.

“While the harrowing aspects of the shooting initially caught the public’s attention, it was Detective McDonald’s expression of forgiveness just months later that captured New York’s spirit,” James said in the letter.

“The first wave of ferries is being named by schoolchildren close to the landings,” responded mayoral spokesman Austin Finan. “We look forward to discussing plans for the next series after initial service launches.”