All four Naval Service Reserve (NSR) motor launches have been decommissioned due to their age, while the strength of the back-up force has significantly decreased and is desperately short of young people.
The 'establishment' (minimum decreed) strength of the NSR was 675 in 2005.
This dropped to 200 during the post-2008 financial crisis and is currently hovering at around 150 effective members. That is half what was recommended and promised in the 2015 White Paper on Defence.
"After years of Department of Defence manpower cuts, recruitment embargoes and neglect the NSR is undermanned and has the wrong membership profile," one NSR source said. He estimated it would take up to three years of successful recruitment to reach the 300 figure.
The problems being encountered by the NSR means it is not in a position to help plug gaps among the ever-decreasing number of personnel in regular Naval Service, which is haemorrhaging more people than any other branch of the Defence Forces.
"The NSR will continue to respond to Naval Service requests for personnel, but there is only so much that a part-time, neglected force with no employment protection in their civilian occupations can contribute," the source said.
The other role of the NSR is to provide an armed naval presence in the strategic ports of Dublin, Cork and Foynes and Waterford.
NSR personnel used to be equipped with four motor launches for this purpose but they have all been decommissioned because they became unseaworthy due to their age.
The Defence Forces press office confirmed the Limerick one was tied up in 2013, those in Waterford and Cork the following year and the Dublin-based one last year.
It said the NSR continues to train on Rigid Inflatable-Hull Boats (RIBS), of the type deployed on vessels by the Naval Service. However, the NSR source said RIBs were not ideal for surveillance purposes and offered no protection from inclement weather.