text:  The Bay of Mariel, 25 miles west of Havana. This morning, nearly 200 Cubans were being loaded onto four boats bound for Florida. It's known as the Mariel Boatlift. Over the course of just a few months, 125,000 Cuban immigrants show up on the shores of southern Florida. Most people end up in Miami looking for work. It's what economists call an immigration shock. It's big. It's very quick. It's all over in a couple months. And it was completely unexpected.