This expression is often used to explain to our car-centric, land-locked culture just how easy and frequent travel between Scotland and Ulster has been over the millennia - small boats can easily cross the North Channel. For example, the Montgomery Manuscripts give this description of Stranraer merchants making a day trip to Newtownards (via Portpatrick and Donaghadee) and were back in Stranraer by bedtime that same day:
As likewise in the fair summer season (twice, sometimes thrice every week) they were supplied from Scotland, as Donaghadee was oftener, because but three hours sail from Portpatrick, where they bespoke provisions and necessaries to lade in, to be brought over by their own or that town's boats whenever wind and weather served them, for there was a constant flux of passengers coming daily over. I have heard honest old men say that in June, July, and August, 1607, people came from Stanraer, four miles, and left their horses at the port, hired horses at Donaghadee, came with their wares and provisions to Newton, and sold them, dined there, staid two or three hours, and returned to their houses the same day by bed-time, their land journey but 20 miles.
Over 400 years later, have a look at the Stena Line website and you'll see it can still take pretty much 3 hours. Albeit you can get an Ulster Fry on the boat and watch a movie - these probably weren't available in the early 1600s.
Let's build a landbridge!The map below, reputedly from 1912, shows that there was an idea to replace the watery North Channel sea with a highway, and to dig a new Northern Channel which would connect the loughs of Foyle, Neagh and Carlingford. No idea of the source of this map, it was posted on Facebook last year and I scooped it. Presumably its purpose was humourous or satirical.
The advert below from a Belfast and Northern Counties Railway brochure of the 1890s shows that even Third Class and Steerage passengers (the bottom rung of the social ladder) could take a day trip from Belfast to Scotland. Depart Belfast at 9:00am, sail to Stranraer, get to Ayr before 2:30pm, leave Ayr just after 6:00pm, back on the boat at 8:15pm and arrive in Belfast before 11:00pm. And you could get your breakfast on the boat.