The US Coast Guard has suspended the search for Eoin Curran, a 30-year-old computer programmer who fell overboard in the Long Island sound on Sunday.
Curran, from Templeogue, was knocked overboard from a Sonar keelboat in a squall, and disappeared before his instructor could get a lifejacket to him.
Curran was not wearing a lifejacket at the time.
The Coastguard began its search, covering a 101 square mile area, but called that search off last night pending further developments.
Curran had only recently emigrated to New York from Ireland, where he had worked for Google.
