The Atlantic side is where you'll find most of the pink sand beaches on Eleuthera. The water can be quite rough on some of these beaches, but others are protected by off-shore reefs, or narrow entrances to bays.
Usually the Atlantic side water gets deep very quickly but the beaches are quite wide and are generally more private than the Caribbean. If you have young children or you want the best swimming experience you may want to favor the Caribbean beaches.
We include the beaches at the top and bottom of the island in the Atlantic side list.