During the present troubles in the north of Ireland the British patrolled the waters bordering the Irish Republic, they had a boat on constant watch in Carlingford Lough.   Irish fishing boats were constantly hauled in by raiding parties from the Brit boats, and this was usually in Irish waters.
Despite constant pleas by the Republics Government this form of harassment continued, remember the old song, Rule Britannia, Britannia waives the rules, and with the Brits it is the same the world over.