A search involving coastguards and the RNLI is under way following reports of a person in the water.
HM Coastguard said it was called to Cardigan, Ceredigion, at 19:45 BST.
A coastguard helicopter and coastguard rescue teams from Cardigan and Moylegrove were called the scene.
A lifeboat from Cardigan RNLI also joined the search, as well as police and the fire and rescue service.