Border Patrol agents spotted 19 suspected illegal immigrants near Dog Beach in Del Mar around 4:30 a.m., according to U.S. Coast Guard Petty Officer Patrick Dunphy.
A short time later, the 25-foot boat believed to be used to drop off the 19 was intercepted by a Coast Guard crew in the ocean about five miles west of La Jolla Cove, Dunphy said.
Three Mexican nationals aboard the boat were taken into custody, and the boat was towed to port, he said.
The 19 people caught in Del Mar were taken to the Imperial Beach Border Patrol station to be processed for deportation, according to the Border Patrol.
In Otay Mesa about 6 a.m., a legal resident on probation for alien smuggling was arrested, along with three Mexicans he allegedly drove into the country.
The driver was caught traveling a smuggling route near Otay Mesa Mountain, according to Jason Rodgers of the Border Patrol. The driver will be held and charged with alien smuggling, he said, and the others will be deported.
On Sunday, a 50-year-old Mexican driving a tractor-trailer packed with 73 people was stopped at the Interstate 8 checkpoint in Pine Valley.
On March 6, federal agents found 25 people from Mexico in a tractor-trailer, and 11 people were found in a truck's hidden compartment on April 29.