Irish border ferry faces choppy Brexit waters As Britain marks the second anniversary of its Brexit referendum on Saturday 23rd June, the border between Northern Ireland and the Irish Republic remains a point of contention in negotiations with the EU. At issue is how the border could remain invisible if much greater trade differences exist between the two regions. It's a worry on the picturesque Carlingford Ferry, a link between north and south that only set sail less than a year ago. A voiced version of an AFPTV report.