text: St. Catherines Island , also known as Santa Catalina , is one of the Sea Islands or Golden Isles on the coast of the U.S. state of Georgia , 50 miles ( 80 km ) south of Savannah in Liberty County .
simplified: St. Catherines Island is an island off the coast of the U.S. state of Georgia , 50 miles ( 80 km ) south of Savannah .