In the summer of 2007, out in the Stockholm archipelago, a half-ton illuminated billboard was anchored to the seabed. Five metres below the surface in the midst of Sweden’s most popular diving waters, where the contrast between the boring sandy seabed and the abundance of marine life in the Red Sea is only too clear. The billboard carried an attractive underwater picture, by the award-winning underwater photographer Alexander Mustard, with a message to all divers that they can book a week in the divers’ paradise of Hurghada in Egypt through the Ving travel agency.

We hired the Big Image printing company to convert a normal illuminated billboard case to operate at a depth of five metres. We brought in professional working divers to lower the billboard to the seabed and make sure the illumination worked under water.

Swimming into the first-ever billboard of its kind is the sort of thing that gets around. Classic word of mouth material.Swedish and international diving publications picked up on the story. It gained viral attention on web sites, blogs, in debates and a video circulated on YouTube.