Up to 50 sailors are sleeping onboard ships during their time off, because they can't afford soaring rents and there is not enough proper accommodation at the naval base in Cork.
PDFORRA, the association which represents enlisted personnel in the Defence Forces, said it is very concerned about the effects this is having on them.
Association president Mark Keane, who works on the naval base at Haulbowline Island, said the sailors are predominantly young and some have been sleeping on the ships for a couple of years.
A report compiled in March 1992 by the then Defence Forces Quartermaster General (equivalent today to a Deputy Chief of Staff)recommended that accommodation at military barracks should be adequate and 'aspire to the standard within the civilian community generally.'
However, the Department of Defence hasn't properly addressed the problem at several military installations, including Haulbowline.
Mr Keane said:
The number is increasing all the time. Unlike other public servants they don't get a rent allowance. If they come from near the base they can still live at home. But we recruit from all over the 32 counties and those who have to come from a long way away simply can't compete for accommodation in rent pressure zones close to the base.
The White Paper on Defence published in 2015 also identified the need for more and better standards of living quarters in Haulbowline.
A year earlier a masterplan for the future development of the whole island was prepared by senior officers at the behest of then Minister for Defence Simon Coveney.
The masterplan identified disused Victorian-era buildings on the base for regeneration. It suggested that one of the buildings, known as Block 6, could be turned into accommodation.
It also suggested that other blocks could be used for research and development facilities and to house a maritime museum.
Mr Keane said the report indicated that it would cost more than €9m to convert Block 6 to accommodation and work on it could start in 2021. However, he said he believed this timeline was 'aspirational' and even if it was adhered to, it wouldn't address the now chronic accommodation crisis at the base.
"We want to see where this plan is going. In short, show us the money to build it."
He said it cannot be good for sailors to end up sleeping in their place of work for lengthy periods.
"It's not ideal sleeping where you work. You really don't have any proper downtime," he said.
Meanwhile, the former head of the elite Army Ranger Wing (ARW) said it was still common that soldiers were sleeping in cars because there was no accommodation at bases.
Former Commandant Cathal Barry said he had personally witnessed this as recently as two months ago at a barracks in Galway.