Paul, you're actually referring to three courses - there are two 18-holes courses at Sea island GC, which is really on St. Simon Island, plus Ocean Forest GC, which is actually on Sea Island. (get it?)
Gary Galyean has two wonderful books about these places. You shoud see his accounts of them, they are definitive and interesting.
Ocean Forest, by Rees Jones, is a private club on land that's at the far eastern tip of the island that also houses The Cloisters. They are run as separate poroperties, so please note, Ocean Frest s not a resort-accessible course
As for Sea island GC, it sits across the waterway on St. Simon Island GC and is part of The Cloisters resort. There are four nines there, including original nines by Walter Travis, Colt & Alison, Dick Wilson and Joe Lee (as I recall). Please note I'm working here w/o my files so this is from memory and close, if not totally accurate.
In 1999, Tom Fazio redid the Colt & Alison and Lee nines to create what's now called the Seaside Course - great setting, lots of marshes, and some typical Fazio big-flourished bunkers and greens. It looks great.
Right around the same time, Rees Jones combined the other two adjoining nines in the Plantation Course, replete with his round, flattish bunkers and peripheral mounding to some extent. It lacks the setting and the marshes that Seaside has.
We had a big rater outing there in March 2000 upon the opening of the new 45-room lodge there at Sea Island GC on St. Simon Island. The consensus was the lodge was spectacular and that while the golf was very nice, the lodge was even better.