Coast Guard officials and social workers are seeing many more Cubans risk their lives on homemade rafts to reach the U.S. this year.
Nearly 3,000 have been picked up at sea or on shore, on track to double last year's total.
The surge comes 20 years after Fidel Castro launched a humanitarian crisis on the high seas, encouraging more than 35,000 Cubans to flee.
President Bill Clinton helped resolve that crisis by announcing a "wet-foot, dry-foot" policy: Anyone caught at sea will be brought back to the island, but almost all Cubans who reach U.S. soil can stay.
Coast Guard records show that another 26,000 Cubans have tried the 90-mile journey since then.
Scholars say at least one of every four rafters doesn't survive.