A Miami-based doctor discovered an empty raft with drinking water still on board a few miles off the coast of Florida on Saturday.
"It was empty but still had some drinking water and that gives me hope that someone rescued them," Cardenas wrote. "This is the reality and despair that those who do not have freedom live under the dirty leg of socialism and communism… #soscuba #sosvenezuela #communismsucks #uscoastguard."
In a video, Cardenas noted that "this is what people are willing to sacrifice for freedom."
The U.S. Coast Guard could not be reached for comment, but it routinely urges potential migrants from Cuba "don't take to the seas."
The doctor’s discovery comes after the island nation was rocked by pro-democracy protests over the summer.