This is the most unusual of the locations in Patch Land. It takes place at the surface of the ocean, but it is less sunny than the rest of Water Land. Water floats freely up and down through the air, as if there are gravitational anomalies in the area, although Kirby is not affected. Tall spires of rock pierce the sky, and waterfalls from up top spill water down to the sea far below. The Dolphin metamortex transformation features in the level. Fossil Reef shares the same theme background music as Deep-Dive Deep.