The answer is no.
The Celtic Sea is the name used by the oil industry and the French for what we call the Western Approaches. See the map in the Related Links, the area of the Celtic sea is highlighted by red dashes, you can see that the Irish Sea is separate to it.
The Celtic Sea is to the south of Ireland and the Irish Sea is to the east of Ireland.
North Sea, Irish Sea, Celtic Sea.
The Celtic Sea and the Irish Sea.
The Irish Sea to it's North and entre, and the Bristol Channel to it's South.
The Irish Sea and the Celtic Sea.
The Irish Sea and the Celtic Sea.
Ireland is geographically part of the British Isles. So on that basis, there is no answer to the question. What you are referring to is the sea between Ireland and Britain. That is the Irish Sea.
The Atlantic Ocean is to the west of Ireland and the Irish Sea is to the east. However there are other seas around Ireland. St. George's Channel and The North Channel are at either end of the Irish Sea, and the Celtic Sea is part of the Atlantic, just south of Ireland.
The Atlantic Ocean, the Irish Sea and the Celtic Sea.
The Irish Sea to the North and the Celtic Sea to the South
North Sea, Irish Sea, Celtic Sea, English Channel, Atlantic Ocean.
There are two. The Irish Sea and the Celtic Sea.