Hi will, it's a great overnight sail. You can ride the falling tide out the mouth if the cape fear as long as the wind
is not against it and conditions are moderate. Presumably you'll catch a northerly forecast
Give yourself some sea room coming into Chas harbor as in leaving, as shanedennis mentioned, basically from sea buoy to sea buoy. No chart in front of me here on my iPhone
so I can't remember exact distances. In general, leaving early from cape fear gives you much of the following day to make your destination
in daylight. It is a long way to charleston from the sea buoy. Chas maritime center puts you close to town and a grocery store.
Same thing heading south, leave early and I think you can make St. Mary's but cutting it close with short days. Can always come in St. Simons but it is not much further to St. Mary's. if conditions and experience allow, you can leave charleston in the early am in the dark, giving you more of a buffer to make landfall before dark.
Cumberland island is a favorite place of ours. Enjoy anchoring
in the Cumberland sound.
Have a great trip-