[00:00.40]Of all the oceans,
[00:01.56]the Pacific is by far the largest,
[00:03.97]stretching almost a third of the way round the globe.
[00:07.05]It's so huge that the current in the South Pacific takes several years to complete just one cycle.
[00:13.46]In an ocean this vast, many animals have to travel huge distances to survive.
[00:19.10]None more so than the sperm whale, one of the greatest voyagers on the planet.
[00:24.65]Every year,
[00:25.44]thousands of bull sperm whales,
[00:27.71]some from as far as Antarctica,
[00:29.85]come to the tropics to breed.
[00:32.43]After 15 years away,
[00:34.46]fattening themselves up in colder climes,
[00:37.17]they are now back and big enough to compete for a mate.
[00:40.93]These warm,
[00:41.87]equatorial waters make ideal nurseries.
[00:45.38]At just a week old,
[00:46.93]this white calf already weighs over a tonne.
[00:49.65]For the next six years he will stay by his mother's side,
[00:53.20]relaxing in these tropical waters where killer whales,his only natural predator,are rarely found.
[00:59.75]But it was in these peaceful stretches of ocean that,
[01:03.14]200 years ago, whales met whalemen.
[01:07.22]