The Naval Service Reserve (NSR; ) is the reserve force of the Irish Naval Service. It is one of two elements of the Reserve Defence Forces of the Defence Forces of Ireland, the other element being the Army Reserve. The NSR was established on 1 October 2005 to replace and reorganise the previous naval reserve organisation, An Slua Muirí, which in turn replaced the fore-runner Maritime Inscription founded in 1940 to act as a Port Control authority during the Emergency (Ireland).