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.
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A wet start as rain continues to move east. It'll eventually dry up and brighten up this afternoon.
A wet start this morning but it'll dry up and brighten up this afternoon.