The Department of Defence has confirmed it intends to proceed with purchasing a new Multi-Role Vessel (MRV) for the Naval Service, which could be used as a hospital ship and would be capable of carrying troops and helicopters for amphibious and airborne landings.
A spokeswoman for the department said planning is "underway on this project".
It is envisaged that it will replace the ageing LÉ Eithne as the Naval Service flagship, and could cost up to €200m.
The new ship is likely to be designed to allow it the capability to carry out numerous different types of missions, not just sea fishery patrols.
Military sources have indicated that it could be used to provide humanitarian aid in times of emergency in Ireland and in other countries where conflicts or climate disaster threaten civilian populations.
It could also be used by gardaí, customs, or the coastguard, where required.
The MRV project is being managed by a civil-military project team and work is ongoing on preparing detailed specification requirements for the ship.
“The cost of the MRV and the timeframe for the build of the vessel will only be known once a tender competition is concluded, when a bidder is selected and a contract awarded,” the Department of Defence spokeswoman said.
Military sources told the they don't expect delivery of the ship until around 2025.
The project team has examined the configuration of other MRVs, notably the New Zealand navy's HMNZS Canterbury.
An MRV could measure up to 150m in length, dwarfing the navy’s largest vessels which are 92m long.
Longer ships will be required in the Naval Service in the coming years because climate change has contributed to far rougher weather and far bigger waves in the Atlantic.
Increased length gives a ship more stability in such conditions.
In addition, the Department of Defence is also planning to purchase new C295 aircraft for the Air Corps.
The current CASAs can fly for nine hours, with a range of 1,500 nautical miles. The new aircraft will have a maximum of 12-hour flight capability and a 2,000 nautical mile range.
