Two years after a B.C. Ferry ran aground and sank, the two crew members on the bridge never fully co-operated with the federal investigation into the crash.

Despite three major studies costing taxpayers well over a million dollars, neither crew member was forced to answer any questions -- and that has some critics comparing the process to a "toothless tiger."

"Basically all we know after all these inquiries is the fact that there's 14 minutes of unexplained activity that caused two people not to pay attention and a ferry to sink," said B.C.'s Transportation Minister, Kevin Falcon.

Opposition leader Carole James said this was grounds to proceed to a public inquiry into the crash.

And the head of B.C. Ferries, David Hahn, told CTV News he was frustrated and disappointed with the Transportation Safety Board investigation, whose results were released today.

But, he added, he wasn't surprised.

It's an immense source of frustration for everyone, including the lawyer for Kevin Hilton, the ship's second officer.

"[The Transportation Safety Board] don't have the powers to cross-examine, it's not done in the open and it's not an effective process," said lawyer Chris Harvey.

The Transportation Safety Board recommends safety improvements, and doesn't lay blame.

But in future, more may be necessary to compel witnesses to testify, says the federal minister responsible.

"We have to look at that, quite honestly, we have to look at it in terms of getting as much information as possible," said Lawrence Cannon, the federal transport minister.

But Falcon said that there was no need for a public inquiry.

"What there is a need for is those two employees to come forward and truthfully testify as to what went on during those 14 minutes," Falcon said. "That's the only piece people don't have."

With a report from CTV British Columbia's Jim Beatty