My safety stop is complete but something out of the corner of my eye distracts me. Still a couple of meters below me, our dive leader, Jaume Pericas is frantically pointing at something. At first I couldn’t work out what he was seeing. Had Jaume spent too much time underwater? Was he seeing an imaginary ghost of Moby Dick? Or did he simply want to ensure that I missed out on the scrambled eggs that so deliciously followed an early morning dive. It occurred to me that I could see something too but my mind was not registering. A dark silhouette seemed to cover the entire ocean floor as if revealing an ancient underwater city. But this was no fantasy, legend or mythical beast – this shadow was alive!…