Martin Barraud working on an installation of bootprints at Slapton Sands, Devon (Picture: There But Not There).
A ceremony has taken place in memory of 749 American service personnel killed by Nazis in British waters as they rehearsed for the D-Day landings.
Exercise Tiger took place 75 years ago, and was the secret mission to prepare for the Allied invasion of Normandy.
The troops were killed on April 28 when a Royal Navy convoy carrying them was attacked by E-boats from Nazi Germany's Kriegsmarine.
The exercise was kept secret for years afterwards.
A set of bootprints for each of the GIs that died have been laid out on Slapton Sands, in Devon, in their memory.
Artist Martin Barraud created the installation which was unveiled by the Remembered charity and will raise money for veteran employment projects.
Mr Barraud also designed last year's There But Not There campaign, which placed silhouettes of First World War "Tommy" troops across the UK, to mark the centenary of the end of the war.
"Last year our Tommy campaign captured the hearts of the nation, whilst giving a substantial boost to the mental health and wellbeing of veterans across the UK," he said.
"A year on and we're hoping the great British public will get behind our D-Day 75 campaign by purchasing their own Bootprints to mark the great sacrifice of our WW2 heroes, in particular those who helped kick-start the liberation of Europe with the invasion of Normandy on D-Day."
Pam Wills, 85, from Devon, was just 10 when Exercise Tiger took place near her home, and her family was evacuated before the exercise began.
She said: "The US soldiers came over and talked to us, they gave us sweets and comics, but they then suddenly disappeared.
"We didn't know Exercise Tiger had taken place, but my father, who was in the Royal Observer Corps watching for enemy aircraft, saw ambulances going to and from Slapton Sands, so we knew something was wrong."
Schools, businesses and communities will be able to purchase commemorative D-Day Bootprints vinyls for £4 each, to be placed in public spaces nationwide.
Commemorative Bootprints plaques made by veterans will also be available for £29.99, with each representing one of the 22,763 British and Commonwealth servicemen and women who were killed on D-Day and during the Battle of Normandy in the summer of 1944.
Mr Barraud said: "Our enduring hope is that every one of the US, British and Commonwealth soldiers, sailors and airmen who gave their lives will have a Bootprint purchased in their memory."