HONOLULU -- Maui Circuit Judge Joseph Cardoza ended four weeks of a hearing on Tuesday for the Hawaii Superferry by ruling to keep the vessel from sailing until an environmental study is done.

Hawaii Superferry officials testified that the interisland catamaran would have to leave Hawaii if it cannot operate while an environmental assessment is performed.

Attorney Isaac Hall said the law clearly stated the assessment must be done before the ferry can start service. Hall represents three groups that have been pushing for the environmental study.

The judge said Hawaii law clearly requires a lengthy, government, public environmental review before the Superferry can operate at Kahului Harbor.

He also found that if it travels before a review, it could pose real threat to endangered species and even the neighbor island's way of life.

Cardoza said in his ruling that he knew that this was a divisive issue and he stressed that despite the outcome, everyone would have to face the situation together.

He expressed his concerns about new technology and its impact on the environment.

"This opens a new chapter in Hawaii's transportation history," Cardoza said.

The ferry has sat in Honolulu Harbor since late August after the Hawaii Supreme Court ruled the state shouldn't have exempted it from an environmental study required by law.

Hawaii Superferry President John Garibaldi spoke outside the courtroom shortly after the ruling.

"I feel personally very, very disappointed for the 300 employees of Hawaii Superferry. They've shown a tremendous amount of support and courage during this entire process," Garibaldi said.

The company also released a written statement: "Obviously, we are disappointed. While the ruling is a loss for Hawaii Superferry and our employees, it is a greater loss for the state of Hawaii."

Garibaldi had said in his testimony that his company was losing $650,000 a week while it did not operate.

The attorney for the environmental groups, Isaac Hall, said he was happy with the ruling. He said it sent a message to businesses to follow the rules.

"But because the state and Hawaii Superferry chose the path of putting their heads in the sand and even denying that this was required they are in this position now," Hall said.

"I agree with Judge Cardoza's ruling requiring the state to conduct an environmental assessment before the Superferry goes into full operation on Maui. This has been a difficult situation for our community and a long court process. I thank the court for its diligence and the public for maintaining its civility throughout the course of this contentious and significant issue. The environmental and economic concerns raised are all certainly important and I believe it is warranted to address mitigation efforts," Maui Mayor Charmaine Tavares said in a written statement.

House Majority Leader Kirk Caldwell said he was "very surprised to see the judge say flat out that the Superferry could not sail."

He said he thought Cardoza would allow the ferry to operate with stipulations. (Learn more about what lawmakers are considering.)

One big question left after the hearing was whether the Superferry's ability to travel to Kauai has also been blocked. The judge said that the Superferry's operating agreement with the state is void, but whether that is meant to prevent all its sailings is not clear.

Meanwhile, the Superferry made it clear it will appeal. However, it was unclear about whether or when it will make good on its threat to leave Hawaii completely to seek revenue elsewhere.