The city’s burgeoning East River ferry service has proven so popular with New York commuters and picture-snapping tourists that its operators had to get bigger boats, Mayor Bloomberg announced yesterday.

The supersize ferries — to be used on weekends — will accommodate 399 passengers, more than double the smaller ferries’ capacity of 149.

In addition to the larger vessels, the city is opening a landing at Pier 1 in Brooklyn Bridge Park, with two slips and extra-wide gangways to allow for faster on and off times.

The privately operated ferries — which are heavily subsidized by the city — cost $4 a trip and $140 for an unlimited-ride monthly pass.

jennifer.fermino@nypost.com