What Lies North of Ireland? Not an Ocean.

Strictly speaking, no ocean borders Ireland's north coast. The island's northern shores face the North Atlantic Ocean—specifically its northeastern extensions:

• North Channel (separating Northern Ireland from Scotland)
• Malins Sea (off County Donegal)
• Rockall Trough (deep-water region further west)

The Irish Sea lies to the east (between Ireland and Great Britain), while the Celtic Sea stretches southward. Ireland is thus encircled by Atlantic margins, not a distinct northern ocean.