Crossover' is a word scientists use to describe dolphins' soaring over seas, their traveling so free and fast, so high-spirited and almost effervescent that their sleek bodies barely skim the waves. The suggestion of splashes from tail and pectoral leaves a luminous wake across the water. For these crossover miles, the dolphins, like their human terrestrial mammal kin, belong more to the element of air than the sea....Held in [the dolphins'] fluid embrace, I pulled my arms close against my sides and our communal speed increased... Racing around the lagoon, I opened my eyes again to see nothing but an emerald underwater blur. And then I remembered what I had either forgotten long ago or never quite fully realized. This feeling of being carried along by other animals was fam
