Of the shipping areas named, “Bailey” is the most northerly, named after a sandbank in the North Atlantic Ocean to the northwest of Scotland. “Malin” is southeast of “Bailey” and is named after Malin Head on the Inishowen Peninsula, the most northerly headland on the mainland of Ireland. “Rockall” is due south of “Malin” and is named after an islet or rock stack in the North Atlantic Ocean thought to be the eroded core of an extinct volcano. The “Lundy” area is furthest south of the four areas and is named after an island in the Bristol Channel.

The waters around the British Isles are divided into 31 such sea areas, also known as weather areas. The U.K. Met Office (officially the Meteorological Office until 2000) issues daily Shipping Forecasts providing weather reports and forecasts for the sea areas around the U.K. and Irish coasts. These are broadcast at four set times daily by BBC (British Broadcasting Corporation) radio on behalf of the Maritime and Coastguard Agency.

The 31 sea areas are named in ongoing consultation with neighbouring countries around these coastal waters. Some names still differ, e.g. the Dutch name the area equivalent to “Forties” after the Fladen bank, while France calls the English Channel sea areas “Dover”, “Wight”, “Portland” and “Plymouth” respectively “Pas-de-Calais”, “Antifer”, “Casquets” and “Ouessant”.

Although most vessels now have onboard technology to provide the Forecast's information, they still use it to check their data.

More Info: en.m.wikipedia.org