A CYLINDRICAL wall 8m tall and capable of flashing digital text and images will go up next month in Marina Bay, in the waters between the Esplanade and Merlion Park.

It will debut during the National Day Parade (NDP), when it will carry real-time video dedications which Singaporeans will send in via multimedia phone messages or the Internet. It will also screen a live broadcast of the Aug 9 parade.

The company behind the project is riding on the NDP to showcase the technology behind its 80-tonne digital canvas and interactive billboard, which cost 'a few million dollars' to build, said its owner, PGK Media.

The chief executive of the provider of digital technology platforms and solutions, Mr Giulio Dorrucci, said the challenge was to make the giant display waterproof, weather-proof and able to float despite its weight.

Below the surface of the water, unseen, will be the cables tethering the cylinder to the seabed, as well as electrical cables and optic points linked to a control centre near the Esplanade.

The modules making up the structure, now being built in several countries around the world, will be shipped here to be assembled in three days.

After National Day, the structure will be dismantled and rented out, for example, for sports events and New Year countdown parties, he said.

Mr Ignatius Francis, the director of marine engineering specialist Singapore Salvage Engineers, confirmed the challenges of putting such a structure on water.

For example, it will need chains heavy enough to keep it from swaying and it will cost more to maintain because sea water is corrosive, he said.

Smaller versions of the cylinder may soon find their way into shopping centres, hosting interactive advertisements. Shoppers will be able to use them to access maps of the mall or even ask shop assistants for the latest promotions, Mr Dorrucci said.

The company is in talks with malls here and those in Dubai and Brazil.

PGK will showcase the small version of the cylinder at next week's BroadcastAsia trade show here in Singapore.