Searchers are still holding out hope that the seven American tourists missing since a shipwreck over the weekend in northwestern Mexico will be found alive, emergency management officials said.

The charter fishing boat Erik, which was carrying a Mexican crew and American tourists, capsized early Sunday in the Sea of Cortez.

A total of 35 people - 18 tourists and 17 crew members - have been rescued since the shipwreck off San Luis, an island in Baja California state, which is in northwestern Mexico.

One person, Leslie Yee, died in the shipwreck, officials said.

The seven missing tourists may still be alive, Baja California emergency management chief Alfredo Escobedo said Wednesday.

The missing tourists may have made it to an island or the coast, Escobedo said, noting that a crewman managed to swim to a naval base and get help.

Don Lee, Russel Bautista, Mark Dorland, Brian Wong, Al Mein, Gene J. Leong and Shawn Chaddock went missing after the fishing boat capsized.

The nationalities of the missing and the dead person have not been officially confirmed.

A U.S. C-130 Hercules is searching Baja California's waters for the missing tourists, while Mexican marines examine the wreck with sonar in case any bodies are inside, Escobedo said.

Three helicopters and two ships belonging to the Mexican navy are taking part in the search operation.

"Priority number one" is to find the missing because the situation becomes more dire "with every minute that passes," Baja California Gov. Jose Guadalupe Osuna said in a joint press conference on Tuesday with U.S. Consul General Steve Kashkett.

Officials are also looking to clear up "the causes of the accident and the conditions in which the fishing boat was operating," Osuna said.

The boat sank about 108 kilometers (67 miles) offshore, Mexican officials said.

Gary Wong, one of the survivors, said he regretted convincing two of his brothers, one of whom is missing, to go fishing with him.

"By this time, the most likely thing is that he died," Wong said.

"We are not going home without his body," Wong said, adding that he had made the same trip the past two summers and never imagined that an accident like this could happen.

Officials have not said what caused the shipwreck, but there are reports that bad weather, including heavy rains and high seas, may have been the reason the Erik went down.

The 35-meter (115-foot) boat offered sports fishing and commercial charters lasting several days and specializing in dolphin, which are abundant in the Sea of Cortez.