BOSTON -- Hundreds of passengers on board the "Massachusetts" were rescued Saturday morning after the 87-foot vessel ran aground and began taking on water near Deer Island.

The Coast Guard received a Mayday call from the vessel around 10:04 a.m.

Winthrop Deputy Harbormaster Chuck Evans said the boat had left Rowes Wharf in Boston for a whale watching trip when operators said it had collided with rocks at Devil's Back Ledge. The vessel had only been a half-hour into its journey when it ran aground. Estimates put the speed of the Massachusetts at about 18 knots.

Passenger Stories | Photos: Passengers Rescued From Sinking Ship

Rescue crews -- including Coast Guard boats and good Samaritans -- were able to safely rescue 168 passengers and six crew members who were on board the sinking ferry. The passengers were taken to Pemberton Pier in Hull, about three miles away.

“I looked down and I could see it looked kind of shallow then the boat jolted forward some people fell back,” said passenger Jeff Picerno. “I had to catch my daughter before she got thrown to the ground.”

It was a scary situation for both passengers and crew.

Sarah Bennett, a tourist from North Carolina, said that passengers were instructed to grab life jackets and move to the top deck. She said she was taken to shore on a lobster boat with about 40 other passengers.

“The captain got on the intercom and told us to stay calm but he sounded pretty nervous so that made me a little nervous,” said Bennett.

Boats from the Massachusetts State Police and Environmental Police pulled along the port side of the sinking ship to effectively provide a bridge for passengers to walk across to the larger Coast Guard rescue vessel.

"As the evacuation proceeded, two shallow draft lobster boats pulled up alongside the starboard side of the Massachusetts and began evacuating passengers from that side," said State Police spokesman David Procopio.

Meanwhile, workers on board the boat spent hours pumping out the vessel, while divers patched the gash in the hull.

"It's a pretty serious accident," Evans said. "Once it goes down, it would be a total loss."

A Falcon Jet crew and Jayhawk helicopter crew were also sent to assist with the rescue.

Four people were hurt including one person with a knee injury and one with a back injury. None of the injuries were considered life-threatening.

Massachusetts Bay Lines Inc., lists the ship on its website as part of its fleet.

"This 100-foot vessel is very popular for VIP receptions, corporate outings, organizational gatherings, and holiday parties," the listing reads.

This isn’t the first incident for the Massachusetts. Back in June 2006, the vessel had a fire in the engine room forcing the evacuation of its passengers. In July 2007, the vessel collided with another commuter boat called the Laura on a foggy morning, leaving a hole in the Massachusetts. No injuries were reported in either incident.

Just after noon, the tour company’s “Freedom” transported the passengers from Hull back to Rowes Wharf.

Massachusetts Bay Lines refunded passengers the nearly 40-dollar trip. They have also suspended all tours for the next few days.

Meanwhile, the Massachusetts was being towed back to port to determine what caused Saturday's mishap.