BY ANDRES VIGLUCCI

Seven South Florida men have been charged in a foiled alien-smuggling venture in which a Cuban man was fatally injured and 31 other passengers from the island were captured on an overloaded 33-foot speedboat near the Florida Keys.

Because of the death, which appears to be accidental, the accused smugglers face life in prison if convicted.

The seven men were on board three speedboats intercepted by the Coast Guard late on Sept. 23. Investigators say they believe two of the boats ferried fuel out to the third and largest vessel, which carried all the migrants.

That main boat, a Scarab, was ''bouncing violently'' as it sped toward Florida in rough seas after the apparent refueling, according to the crew of a U.S. Customs and Border Protection airplane that was following it.

The description was quoted in documents filed in federal court.

When the Scarab was intercepted and boarded by the Coast Guard at about 11:45 p.m., one of the passengers was found lying on deck, ''unconscious and bleeding from his head,'' the documents say.

The man was declared dead at 2:50 a.m. Wednesday after arriving by helicopter at the Coast Guard air station at Opa-locka Airport. Authorities were withholding his name pending notification of relatives, U.S. Immigration and Customs Enforcement spokeswoman Nicole Navas said Monday.

Piloting the Scarab were Elieten Mendoza Zaldivar, 35, of Miami, and Alexis V. Cervantes, 34, of Tamarac, authorities say.

Arrested with them were the crews on the other two boats. All were charged with alien-smuggling conspiracy leading to a death. Three were identified as Hialeah residents: Reynaldo Crespo Martinez, 29; Humberto Carrazana, 25; and Michael Lopez, 30. Also charged were Brainer Gomez, 26, of Carol City, and Arley Ceballo Gonzalez, 31, of Miami.

The Scarab and one of the refueling boats were detected by the customs aircraft's radar while tied together about 40 miles west of Williams Island in the Bahamas, investigators said in an arrest affidavit. The third boat joined them about 50 minutes later. Men on the boats were seen pitching what appeared to be fuel containers into the water, the airplane crew reported.

Three Coast Guard cutters stopped the three boats, which had scattered, at around 11:45 p.m., about 45 nautical miles from Key Largo. There was no use of force, authorities say.

A Coast Guard rescue swimmer helped hoist the unconscious man to a medical evacuation helicopter. Paramedics pronounced him dead on arrival at Opa-locka.

The 31 other passengers are being held as potential witnesses in the criminal case.

Since December 2007, 65 Cuban migrants are known to have died at sea while attempting to reach Florida, the Coast Guard says.