A search has been called off for the night at the East Pier in Howth for a man seen in the water.
Emergency services were informed at 5.21pm.
Some items of fishing gear were found near the area where the person was seen.
Weather conditions at the time were described as “rough” with force 5 to 6 winds.
The Coast Guard helicopter searched the area assisted by Howth Coast Guard, two RNLI lifeboats, as well as Gardaí, Fire Brigade and ambulance service teams.
The Garda Air Support Unit was also involved in the search.
This evening the Coast Guard said the operation had been stood down at 7.35pm due to fading light.