several battalions were supplied with rigid dell quay dory craft for patrolling waterways shared with the republic of ireland in an attempt to prevent gun-running across these narrow channels such as carlingford lough. assisted by land-based decca marine radar mounted on a land rover, deployed at killowen point. these boats were armed with bren light machine guns and carried a carl gustav 84mm anti-tank weapon in addition to the rifles and sub-machine guns normally carried by soldiers. the shore-based dories proved inadequate and a paper was submitted by 3 udr in 1972, recommending a naval vessel to be stationed in the centre of carlingford lough to assist with the suppression of gun-running. this suggestion was adopted and to the end of the security situation a small warship was on station off the coast of the warrenpoint/rostrevor shoreline. this intervention was called operation grenada. gun-running across these coastal estuaries ceased as a result. 3 udr continued to dories and the radar stretches of the coast. the radar was withdrawn from use and later dispatched to the south atlantic during the falklands war on board the ss atlantic conveyor and lost when the ship was sunk after being hit by two argentine exocet missiles. the 4th battalion also carried out waterway patrols on upper and lower lough erne.