BURNS HARBOR, Ind. (CBS) — A U.S. Coast Guard crew rescued two men early Wednesday, after their boat slammed into a breakwall in Lake Michigan offshore from Burns Harbor, Ind.

A distress call came in to Coast Guard watchstanders in Milwaukee around 3:15 a.m. The Coast Guard crew in Michigan City was notified, and found the two men in the wrecked boat without life jackets.

The boat had slammed into the large rocks in the breakwall, and was sinking, the Coast Guard said.

The men both had to be taken to a hospital.

One of the men, a passenger on the boat, had suffered a head laceration that left him in critical condition. He was taken by medical helicopter to Advocate Christ Medical Center in Oak Lawn after the Coast Guard brought him back to the Portage Municipal Marina.

The other man, who owned the boat, suffered injuries to his arms, ribs and legs. He was being treated at Porter Memorial Hospital in Valparaiso, Ind.

The owner is believed to have just bought the boat on Tuesday, the Coast Guard said.

While the owner’s experience with boating is unknown, the Coast Guard nevertheless urges boaters to take safety courses every year before going into the open water. The U.S. Coast Guard Auxiliary and the U.S. Power Squadron are among the organizations that offer boat safety classes.

The cause of the accident is under investigation, according to the Coast Guard.