‘Think dogs in wetsuits,’ said our guide of the cluster of sea lions at our feet on San Cristobal, one of the remote collection of 19 volcanic Pacific islands slap bang on the Equator that make up the Galapagos. Struggling awkwardly up black lava rocks or even there along the sands of Cerro Brujo, the most beautiful beach I have ever seen, the 31-stone beachmaster and his harem looked ungainly, even ridiculous.