The choppy water problem while running the AICW’s passage across Georgia’s St. Andrew Sound results from the Waterway’s passage practically out into the briny blue, in order to clear Horseshoe Shoal, which occupies the Sound’s mid-width. Recognizing the potential for very dusty crossing here, the US Army Corps of Engineers has provided an alternate route, known as Umbrella Cut, BUT low water depths on this alternate passage can run as thin as 4 1/2 feet.
Just a note that I recently rounded the north end of Cumberland Island and used the pass out of Saint Andrew bay marked “the hole” on the chart. Once around the north end of Cumberland it became apparent how dangerous this area is with shoals and breaking waves on both sides. Prudent cruisers should avoid this area at all cost. You could easily lose your boat here. The local tow boat captain told me he is not allowed to respond to calls out there. Too dangerous.
There is another route to avoid the worst of St Andrews Sound. You can go around the west end of Horseshoe Shoal and have over 8′ of water except for one small spot. Just south of G7 buoy, there is a sharp peak that rises to 4′ MLW. The charted depth of 8′ here is not accurate.
Richard Ross M/V Chez Nous