"Shark Bay never ceases to surprise me. I was focusing on another area of the seabed when this composition literally jumped out of the blue sea. With closer examination, I recognise the dark bands in the frame are seagrass belts. What is special about these few bands of seagrass is that they have managed to form barriers that separate the ocean floor by different depths of seawater. This then gives rise to the colour transition at either side of the barrier. Although I had to react incredibly quickly to compose this, I'm pleased the division of lines is presented with perfect aspect ratios. I love the mysterious feel about this unorthodox pattern. The image is best appreciated when seen in a large format to visualise the fragile seagrass network." Yi Sun