Litter on Britain's beaches reached a record high in 2003 and is up nearly 100% on 10 years ago.
Beach visitors are urged to take their rubbish home
The Marine Conservation Society survey found rubbish at the coast has reached its highest level since Beachwatch monitoring began in 1993.
The society has called for a change in public attitudes to the problem and said legislation had little effect.
Sewage-related debris had also increased for the first time in five
years, the survey showed.
Litter was up by almost a third on 2002 results and by 99% compared with Beachwatch 1994.
More than 2,500 volunteers helped to clean and survey 244 beaches making up 135 kilometres (84 miles) of coastline over two days last September.
Litter on UK beaches
England: 2,655 items/km
Wales: 2,455 items/km
Scotland: 1,536 items/km
Channel Islands: 1,125 items/km
Northern Ireland 807 items/km
Beach visitors were found to be the biggest source of rubbish, contributing 36.7% of all waste.
Fishing debris accounted for 14.6%, sewage-related debris 7.8%, and shipping litter 2.0%.
Andrea Crump, MCS litter projects co-ordinator, said: "Tourists will choose a beach because of its beautiful scenery and clean sands, then spoil the beach for other users by leaving their rubbish behind.
"Every single piece of rubbish has an owner and every single person can make a difference by making sure they take it with them when they leave the beach."
Minister for Rural Affairs and Local Environmental Quality Alun Michael said the government believed in taking action to address the issue.
The MCS wants the Government to introduce more effective laws to prevent littering by the public.
It also wants unnecessary plastic packaging reduced and a new plastic bag tax, successfully introduced in Ireland.
Plastic items accounted for more than half of the litter found, including 5,831 plastic bags - the equivalent of 43 bags for every kilometre of coastline surveyed.
Every year thousands of animals are thought to die because of being caught in, or eating, litter.
Of the increased sewage-related debris, cotton buds made up 83% of it.
In total, 17,981 cotton bud sticks were found, of which 56% were discovered on one Scottish beach.
The MCS said this indicated that the message not to flush them, or anything plastic, down the toilet was not getting across.
The concentration of rubbish varied across the UK, with England having the highest volume.
The Channel Islands and Northern Ireland both recorded a decrease on 2002 levels.