The water close to shore tends to be murky unless the beach is rocky. The water temperatures are not as warm in the winter as the water in the Caribbean. Although, in the summer the water gets up into the 80's. The beach is good for sunning but not popular for swimming. The Eden has a large pool so that should not be a problem for the swimmers.
Wind is always a problem in any desert.
In the winter time cold north winds can blow for days keeping the hardiest of fisherman off the water. However, when the winds are down, the sun is warm and temperatures go into the high 70's, it is wonderful. Nights can be brisk so bring a jacket. All and all the Eden is a fun vacation for most people, but I'm not into golf and the all inclusive routine gets boring. To me its important to get away from the resort and see the interesting sites around the area.