HONOLULU -- Protesters overwhelmed the Coast Guard in waters off Kauai on Monday night and the crew members failed to enforce a security zone around the Hawaii Superferry.

The Coast Guard released a statement late on Tuesday afternoon saying "based on the current situation in Nawiliwili, the Superferry would not been able to safely transit into the harbor."

Coast Guard officials refused on-camera interviews to explain what went wrong on Kauai and why they originally assured the Superferry they could handle the protesters. At mid-afternoon on Tuesday, the Coast Guard admitted it could no longer guarantee the ferry's safe passage into Nawiliwili Harbor.

Coast Guard crews in four boats were out-maneuvered by the 60 or so protesters who were swimming or on surfboards and bodyboards in Nawiliwili Harbor.

The crew members on an inflatable Coast Guard boat tried to grab a surfer's board, but lost their grip and the surfer was able to paddle away. Surfers even splashed the Coast Guard crews in their boats, taunting them.

Some Superferry passengers were upset that the Coast Guard could not stop the protesters in the water.

Daniel Scott of Kaneohe accompanied his family of seven on the failed ferry trip.

"I thought it was a shame that the Coast Guard wasn't as prepared as they could have been," Scott said.

The Coast Guard was able to make only one arrest, pulling a surfer out of the harbor, board and all.

The crews on the scene chose to use minimal force, because there were no lives in danger, a Coast Guard spokesman said. He said the Coast Guard did not want to risk injury of the protesters or its own crew by using physical force.

Hundreds of protesters back on shore shouted at police as they took people into custody. Some surfers and swimmers paddled along the shoreline as officers followed them from shore, trying to arrest them when they came in.

Kauai police took seven men and four juveniles into custody and booked them for misdemeanors and petty misdemeanors, including obstructing a government operation, criminal trespassing and disorderly conduct.

So far, it does not appear they will face tougher federal charges that bring up to 10 years in prison and a $10,000 fine as the Coast Guard originally threatened. Police on Kauai said the cases will probably be prosecuted in state court with up to one year imprisonment and fines up to $2,000.

Some Superferry customers wondered how effectively the Coast Guard can protect Hawaii harbors and ships against terrorists if it could not even stop a bunch of protesters in the ocean.

The Coast Guard said its crews on Kauai had weapons and ammunition that they would have used if the situation had required deadly force, but in this case, the Coast Guard called it a peaceful demonstration.