One of the most memorable moments of my life was snorkelling in the Galapagos Islands and getting close to a giant Manta ray. Despite being over 5 metres wide these creatures are graceful and benign and present no danger to humans. They are continually in motion, feeding on plankton and must move in order to breathe and can only swim forwards. They can go up or down so to change direction may loop around. I approached this one from behind and got within a couple of metres of the huge majestic ray, it wheeled around took a look at me spluttering through my snorkel then headed off into the deep blue. Mantas are considered one of the most intelligent fish in the sea. They have become a big attraction worldwide for diving and snorkelling tourism. Though they have long been fished for subsistence purposes, Mantas and other rays are now under threat for their use in oriental remedies, as the Chinese believe their gills are a miraculous cleansing tonic, though there is no evidence to support this. In Ecuador, Brazil and Colombia there are proposals to protect the species, but sadly this attitude is not universal.