Iroise Sea

Iroise (/ɪˈrwɑːz/) or the Iroise Sea (French: mer d'Iroise [iʁwɑz]; Breton: An Hirwazh) is the part of the Atlantic Ocean which stretches from the Ile de Sein to Ushant off the coast of Brittany in north-western France. It is contained within the Celtic Sea, bordering the remainder of the Celtic Sea to the north and west, and the Bay of Biscay to the south. It is one of the most dangerous seas in Europe for sea-going vessels. In winter, there are often violent storms with huge waves. It is also one of the richest areas for marine life and was designated as one of UNESCO's biosphere reserves in 1988 and as France's first marine park in October 2007.

The name is first recorded in the Neptune francois of 1693 as Le Passage de l'Yroise (passage = "channel"); as Passage de l'Iroise in the 18th century; as Iroise in the 19th century; and as mer d'Iroise (mer = "sea") in the 1970s, by the seabed exploration industry. The name appears to have been fixed not by local seafarers but rather by staff at the naval base at Brest. The 18th-century maps identify "Passage de l'Iroise" as the channel leading north-west from Pointe Saint-Mathieu and keeping south of Ushant (Ouessant) and the Ponant Islands. From the 19th century, the term Iroise encompassed all the sea along the west coast of Brittany between Ouessant and Sein. While this remains the limit used by mariners, some twentieth-century sources have used mer d'Iroise to denote the entire Celtic Sea as far as Ireland and Great Britain.

The meaning of Iroise is obscure; theories include:

From the 1990s, "Iroise" became popular in Finistère in the name of many local businesses and associations. The Pont de l'Iroise bridge was opened in 1994.

in maritime weather forecasts by Météo-France and Spain's AEMET, "Iroise" denotes the sea area east of a line from 48°27′N 6°0′W / 48.450°N 6.000°W / 48.450; -6.000 to 47°30′N 6°0′W / 47.500°N 6.000°W / 47.500; -6.000; this corresponds to the northern part of the UK shipping forecast sea area of Biscay.

The Iroise coastline consists of a rich variety of beaches, rocky cliffs, sand dunes, coves and islands such as the Île de Sein and the Island of Molene.

The considerable differences in depth and the adjacent English Channel create the strong currents through the Iroise. High tides in the Channel bring about strong north-easterly currents, which reverse at low tide. The currents can reach particularly high speeds at the Raz de Sein or the Goulet de Brest.

Many lighthouses were erected in the area to guide sailors. Many local legends describe lost ships and tragedies at sea.