Devils Reef is located at the western end below the high cliffs of Marfa. It's an exciting dive with deep vertical drop-offs to depths up to 50 meters, sloping down to even deeper water. An old cave with stalactites is found on the southern side of the wall together with a few other caves and caverns. Caution because of the silt that gets kicked up when entering these caves. There's also a big grabbing anchor embedded in the area below the drop off.