The former naval vessel LÉ Emer has been sold at auction in Cork for €320,000.
The ship, the oldest in the naval service fleet, was bought by a Nigerian company director.
He said he has yet to decide whether to convert it for pleasure use or use it as a commercial security ship off west Africa.
There were two other bidders, one from Cork and the other based in the UK.
The LÉ Emer is due to be replaced by a bigger ship, the LÉ Samuel Beckett, early next year.