Firefighters were still carrying people away on stretchers an hour after the crash. The most seriously injured person had a severe head wound from falling down the stairs. Most injuries were minor.
More than 340 passengers and crew members were on board the ferry from New Jersey, one of many which carry commuters to the island of Manhattan.
Dee Wertz was on shore waiting for the ferry and saw the impact. She said she had been talking with a ferry employee about how the boat's captains had been complaining lately about its manoeuvrability.
"He was telling me that none of these guys like this boat," she said. "It was coming in a little wobbly. It hit the right side of the boat on the dock hard, like a bomb."
The ferry, built in 2003, had recently undergone a major overhaul which gave it new engines and a new propulsion system, but officials said it was too soon to tell whether they played any role in the crash.