Passengers aboard the Seastreak Wall Street said dozens of people who had been standing, waiting to disembark, were hurled to the deck by the impact.
"We were pulling into the dock. The boat hit the dock. We just tumbled on top of each other. I got thrown into everybody else. People were hysterical, crying," said Ellen Foran, 57, of Neptune City, N.J.
The accident, which ripped open part the boat's hull like an aluminum can, happened at 8:45 a.m. at a pier near the South Street Seaport, at Manhattan's southern tip. Firefighters carried people away on flat-board stretchers as long as an hour after the crash.
About 330 passengers and crew members were aboard the ferry, which had arrived from Atlantic Highlands, a part of the Jersey Shore still struggling to recover from Superstorm Sandy.
Passenger Frank McLaughlin, 46, whose home was filled with 5 feet of water in the storm, said he was thrown forward and wrenched his knee in the impact.
He said some other passengers were bloodied when they banged into walls and toppled to the floor.
Officials said "about 57" people were injured, two critically. Of the 11 people seriously injured, the most serious had suffered a head injury falling down the stairs. Most injuries were minor.
New York City's transportation commissioner, Janette Sadik-Khan, said the ferry was coming in at 10 to 12 knots, or about 12 mph, when it collided with one slip and hit a second.
Dee Wertz, who was on shore waiting for the ferry, saw the impact. She said that just moments before it hit, she had been having a conversation with a ferry employee about how the boat's captains had been complaining lately about its maneuverability.
"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, a catamaran built in 2003, is just months away from undergoing a major mechanical overhaul.
The marine industry magazine MarineLog reported in August that the ferry's water-jet propulsion system was replaced with a new system of propellers and rudders to save fuel costs.
After the impact, the boat was able to dock normally. Wertz said passengers raced off once the ramp was down.
"I think people just wanted to get the heck off the boat as soon as they could," she said.
People answering the phone at Seastreak's offices in New Jersey referred questions to a lawyer, who did not immediately return phone messages.
Police said the boat's crew passed alcohol breath tests given after the crash.
Ferry accidents happen every few years in New York. In 2003, 11 people were killed when a Staten Island Ferry crashed into a pier on Staten Island after its pilot passed out at the wheel. Three people were badly hurt and about 40 injured when the same ferry hit the same pier in 2010, because of a mechanical problem.
The National Transportation Safety Board said it had dispatched investigators to the scene.