The boy is believed to come from the local area and has not yet been named. He is said to have been in the sea just after 4pm this afternoon with a friend when he disappeared.
Sussex Police began searching their area assisted by the local coastguard and other emergency services around the West Beach area of Newhaven.
More top news
James Wright has your evening forecast for the east of the region.
James Wright has the evening weather forecast for the west of the Meridian region.
A man who was hounded by the council over £8.62p claims he was forced to take his wife's ashes to the town hall to prove she had died.