SAN DIEGO — U.S. Border Patrol agents report that more and more migrants are risking their lives by swimming in the Pacific Ocean while trying to enter the country illegally.

The agency is reporting that in the month of May, there were at least five recorded instances in which migrants swam across the maritime boundary line.

All together, seven migrants were apprehended while nine managed to swim back to Mexico before agents could reach them, according to Border Patrol.

Border Patrol says in one case off the coast of Imperial Beach, the U.S. Coast Guard responded to the area but when the swimmers realized they had been spotted, they all turned around and swam back into Mexican waters. 

According to Border Patrol, historically swimming is a very dangerous method of illegally entering the U.S. as smugglers risk the lives of migrants by “exposing them to the harsh forces and dangers of the ocean.”

Migrants usually swim during the cover of night due to their false assumption that they can avoid detection, but many are spotted by surveillance systems employed by Border Patrol, says the agency.

At night, the temperature along the coast drops dramatically and the water can become frigid and turbulent.

According to Border Patrol, coastal waters near the border are also known for rip currents, which are hard to detect and can rapidly pull people away from shore and out to sea.

“Swimming across the maritime boundary line is extremely dangerous for even the most experienced swimmers,” said San Diego Sector Chief Patrol Agent Aaron Heitke. “Smugglers do not care about the lives they endanger; and continue to send migrants who are ill-equipped to deal with the frigid and dangerous waters of the Pacific Ocean.”