Point the bow at the razor horizon and leave the coast behind. As the seafloor drops away to 400 metres...

Oceanic bottlenose dolphins play on the bow, leaping, cavorting and blowing bubbles....

Just beyond the territorial boundary of New Zealand, marine scientist Jochen Zaeschmar takes aim at a pod of pilot whales....

In calm water far out to sea, a group of pilot whales—including some juveniles—rests on the surface between hunts. Some...