evidence: The Irish government complained to British ministers about the alleged harassment of vessels in Carlingford Lough by a patrol boat manned by Royal Marine Commandos, in 1991. [...] The brief added that the lough provided "a very real potential opportunity for terrorists". The memo noted that on 21 October 1991, the crew of one yacht, Gurlough, complained to the Irish government and made a number of allegations a boarding party of Royal Marines had searched it in Carlingford Lough.