I ran the first running of this marathon. It was well-organized for a first year race. You could tell it was organized by runners.
Really flat course. The only "hill" is going over the drawbridge leaving the beach in the first mile. Basically a double loop course with the majority through neighborhoods. I found the course boring for a "beach" marathon. All but the first mile is run off the island.
It is a point to point course that starts close to Wrightsville Beach and ends at Mayfaire Shopping Center off the island. Runners are bused out to the starting line. There is limited parking at the start line and I think they bus back there after the race. If you are riding the bus from finish to start then you need to get there pretty early. Shell Island Resorts is the host hotel has shuttle to the start and back from the finish. I recommend staying there.