What happens to grains of sand at high tide?
12 October 2011 Last updated at 09:56 BST
A scientific experiment is taking place on Perranporth beach in Cornwall that could one day help protect Britain's coastline from rising sea levels and erosion.
Experts from the UK, Australia and America have rigged testing equipment including forty metres of scaffolding to discover what happens to grains of sand at high tide.
Richard Westcott reports.