Whilst out for a walk on Littlehampton Beach I saw a 'beach clean' sign and went to investigate. Turned out it was a corporate litter pick organised by the Marine Conservation Society, and they were logging bits of litter and weighing. Asked if I could join, and they said yes, as long as I did it outside of their area! Collected a smallish bag of litter in 30 mins; mostly rope and fishing line. They collected 3kg!