Houses For Sale Mariners Cay subdivision Folly Beach SC. MLS real estate listings for sale in Mariners Cay Folly Beach SC by price, street, age, list date, bedrooms & more Mariners Cay Folly Beach SC. Currently, Mariners Cay in Folly Beach SC has a total of ten listings on the local MLS for sale with an average price point of $406,275, the max being