The Baradin Sea is a portion of the Great Sea off the coast of Khaz Modan and Lordaeron. The sea contains nearly one hundred islands, many of which are under the domain of the Kingdom of Kul Tiras. On its coast are several of the most prominent ports in the eastern kingdoms, including Menethil Harbor, Hasic, Stromgarde, and several naval bases of the Grand Alliance. It is inhabited by murlocs and crocolisks in the shallows, and crabs and sharks in the deeper water.
The sea has been home to a long string of naval battles over control of the area including the famous Battle of Baradin Bay.
Following the Great Cataclysm of 623KY, an earthquake-triggered tidal wave swept through the bay, flooding several of its islands and Menethil Harbor. Kul Tiras is still rebuilding after the disaster to this day.
Adapted from Wowpedia.