The reduction of the naval service to two operational ships is "extremely worrying", according to the Tánaiste and Minister for Defence.
The Naval Service has said that currently only two vessels are conducting coastal patrols and that in a move prompted by an ongoing recruitment crisis, a third ship will be kept on stand-by.
The navy noted that the total number of new recruits to date in 2023 is 37. Last year the total number was 28.
Speaking on RTÉ's News at One, Micheál Martin said he believes that a "more radical" approach to recruitment is needed as the conversion rate for those who apply to join and those who are actually inducted is "far too low."
"We are short a lot of specialists for ships," he added.
The Tánaiste said direct entry without constraints, which has been the case up to now, must be considered and HR within the naval resources has to be looked at also.
He said young people look at employment differently now compared to previous generations and "we have to respond to the challenges there."
He referred to a number of factors around these challenges, stating how other sectors like pharmaceuticals are offering employment opportunities to people.
Mr Martin said some improvements are being made, describing how the Air Corps has expanded, "which enhances significantly" maritime surveillance.
He said there are various forms of surveillance and intelligence between member states and they are all inter-dependent to combat drug trafficking and other criminal operations.
"That is a feature of modern policing and a modern way of combating terrorism and drug trafficking."
