The largest-brained animal that ever lived. Pods of females and calves rest at the surface between 1km-deep squid hunts.
Sperm whales have the largest brain of any animal in Earth's history — 8 kg in adult males. They dive to depths beyond 2,000 metres to hunt giant squid, holding their breath for 90 minutes at a stretch, and surface only briefly to recover before diving again.
Sri Lanka's Trincomalee coast is one of the world's best sperm whale destinations — pods of 10–30 females and calves resting at the surface between hunts, Mar–Sep. Dedicated whale-watching boats are the encounter setting; in-water swims with regulated operators (snorkel, never scuba) are possible.
Their click-trains echolocate at over 230 decibels — the loudest sound made by any animal on Earth — and can stun prey or be heard underwater from kilometres away. Hover quietly at the surface and you can hear the clicks vibrate through your chest.
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1 destination across Indian Ocean — peak seasons vary by location, so plan your trip around the right destination AND the right month.
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