St. Marys Intracoastal Gateway Marina.

St. Marys Intracoastal Gateway Marina. - As the Gateway to Cumberland Island, St. Marys offers a laid-back vibe with southern charm perfect for relaxation or an adventure. We’re the southernmost point along Georgia’s 110-mile coastline and are easily accessible from the ICW from the St. Marys/Cumberland Sound Entrance. The channel through the sound is simple to follow. Just, exit the sound and head west into St. Marys River keeping in the deep channel before finally turning north to the marina. There are no bridges to navigate but there are dramatic differences between high and low tides on the Georgia Coast.