Since terrain procedural modeling is widely adopted for the virtual natural scene generations in the game design, movie industry, and digital arts, lots of advanced techniques have been explored by researchers to procedurally synthesize a large variety of different types of terrain and landscapes. In this paper, we present a novel approach to generate a special type of landscape -- the Great Barrier Reef -- an amazing natural landscape that is currently being ignored. We propose a hypothesis that the Great Barrier Reef is grown with the diffusion-limited aggregation (DLA) model and simulate the DLA process to generate the Great Barrier Reef procedurally. As presented in the results, the procedural Great Barrier Reef generated with our approach looks natural when compared to the photos of the real ones.