Police are appealing for witnesses to an assault.
The victim, an 18-year-old man, was involved in a altercation with another man and left with a large cut to his head which required hospital treatment.
It happened on The Esplanade, opposite The Royal Hotel, Bognor, at 6.15pm on Monday.
Sergeant Chris Pipkin said: ‘We need to speak to anyone who might have seen what happened and not yet spoken to police.’
A 26-year-old man from Bognor has been arrested on suspicion of grievous bodily harm.
Anyone with information, should call police on 101 or use Crimestoppers anonymously on 0800 555 111.