Galway Bay is full of fishing and shipping boats. Tiny towns beside the sea offer fresh oysters, mussels, crab, and local salmon from boats and other fishing methods; I wrote about what we ate in these posts: Monk's Pub, Ballyvaughn Ireland and Coole Oysters. The city of Galway has berths for ocean-going cargo ships, though it's not a massive container port; the scale of ships is still a picturesque and modest.
At low tide in the small harbor at Kinvara the little fishing and pleasure boats we saw were resting on the mud:
We also stayed overnight at Killybegs, the largest Irish fishing port for the Atlantic. At night from our room we could see the big trawlers in the harbor:
In Dublin our B&B on Clontarf Road had a view of the ferry boats that cross from Ireland to Wales and elsewhere across the Irish Sea. We walked out towards the islands that face Dublin.