I was on a ship in the midst of it as well.
On the morning of the 17th, the pleasure craft Olo Yumi with 52 persons sank when the people on board panicked, ran to the stern, and caused water to come over the transom. The helicopter on patrol from cutter Courageous sighted the people in the water and began rescue operations. The cutter, a few miles from the disaster, broadcasted the emergency. Arriving, Courageous launched her boats, lowered cargo nets, and put swimmers in the water. She along with Coast Guard helicopters rescued 38 and recovered 10 bodies. These refugees had been among those housed in the Peruvian Embassy. One survivor, a 15-year-old girl, lost both parents, both sisters, and a grandparent. The boat had been grossly overloaded. Admiral Stabile sent the following Telex message to the Cuban Border Guard:
THE 35 FOOT VESSEL "OLO YUMI" NUMBER FL4860CU DEPARTED MARIEL HARBOR AT NIGHT 16 MAY 1980 WITH 52 PERSONS ON BOARD. THE VESSEL CAPSIZED AND SANK ABOUT 0830 17 MAY 1980 25 MILES NORTHEAST OF MARIEL. TEN PERSONS ARE DEAD AND FOUR REMAIN UNLOCATED. COAST GUARD CUTTERS AND HELICOPTERS HAVE RESCUED 38 PERSONS FROM THE WATER. TEN OF THESE PERSONS ARE SERIOUSLY INJURED. THIS MARINE TRAGEDY HAPPENED BECAUSE TOO MANY PERSONS WERE PUT ON BOARD THE SMALL BOAT.
http://www.uscg.mil/history/articles/USCG_Mariel_History_1980.asp
Twas a snafu of epic proportions.