Now, U.S. Border Patrol officials say they'll deport anyone caught entering illegally by sea. Deportation means violators could be charged with a felony and prison time if they're caught again.
Steve Pitts, a Border Patrol spokesman, said they hope the stiffer penalty deters migrants.
"The chances for those boats capsizing out there is extremely high. And we're trying to prevent death, so we're trying to deter people," said Pitts.
Two migrants drowned in San Diego last year. U.S. and Mexican civil-rights groups and researchers estimate more than 6,000 people have died crossing over land in the last 15 years.
Border researchers Wayne Cornelius and David Fitzgerald at the University of California-San Diego, who interviewed thousands of would-be migrants in Mexico, found that knowing someone who died crossing the border does not dissuade people from trying themselves. The researchers also discovered that tougher border enforcement does little to deter migrants.