A young sperm whale.

THE ATLANTIC OCEAN WAS ROUGH that morning. We had to sail for a couple of hours to reach the open sea, where a pod of feeding sperm whales had been sighted by the vigia, a land-based observer who once worked for the whaling industry.
The rubber dinghy was equipped with two powerful engines, and Manuel, the captain, managed it with laudable skill. We had to ride the billows, and the situation worsened when it started to rain. After 30 minutes, though wearing my wetsuit and oilskin windcheater, I was drenched.
Manuel suggested that we wait at the nearest port until the storm passed. In the little harbour of Porto de Aguada, once used for commercial whaling, we found a sheltered dock and a simple pub full of local fishermen.
Typically for a little island far from the mainland, after about an hour the sea was flat, the mist had disappeared, brilliant colours reflected sunlight and our pod of sperm whales could still be seen by the vigia. We soon reached them.
Breathe. Stay calm. Dont fling yourself onto them or youll drive them away. Move slowly and deliberately. Paul, the biologist, would repeat this rigmarole word for word, a mantra Ill never forget.
He kept working frenetically, making notes and taking pictures of sperm whales for photo-identification.
I felt as if I was in a dream. We were surrounded by a pod of female and juvenile sperm whales, quietly petting each others enormous heads and gently rolling close to the surface.
Manuel stopped the dinghys engines. The sound of the waves and the cries of the gulls were interrupted only by the powerful breath of the cetaceans, soon followed by the clicking of cameras.
Unexpectedly, the huge head of an old female surfaced close to us, 3-4m ahead of the boat. She rotated on her axis, perfectly upright in the dark water, and gave us a piercing glance before sinking.
My heart seemed to stop. I couldnt focus or take a picture. We had all held our breaths and been left speechless.

THE FEMALE CAME BACK alongside the dinghy, took a deep breath and lowered her huge head, arching the posterior part of the back and lifting her tail fluke as she dived.
Her examination of us had satisfied her: we were not hunters, nor food.
I damned my choice of a camera with a 300mm lens, but Ill never forget the emotions of that morning.
Even veterans with thousands of dives and skilled professionals engaged in all kinds of work related to the sea are amazed by cetaceans.
Manuel managed to cross the path of another adult sperm whale. When we were about 80m away from it he gave me the signal and I glided into the acoustic world of marine mammals.
I couldnt see anything, but I felt the sperm whales clearly. Their echo-location is powerful, and they were analysing me with their sonar.
Almost all toothed whales use echo-location as the primary means of perceiving their murky underwater world. A staccato burst of clicks bounces off an object such as a fish and echoes back to the whale to be received by different organs.
The animal hears this echo as a three-dimensional image possessed of a certain shape, material density and distance.
Recent evidence suggests that sperm whales may use echo-location to attain a uniquely sophisticated level of interpersonal communication. They vocalise their own clicks back and forth to one another, interpreting them not as sound but as three-dimensional moving images that unfold directly inside their heads.
Sperm-whale echo-location follows the same fundamental laws of acoustics that produce sonar imaging in submarines and ultrasound imaging in pre-natal care.
For me, nothing can equal the suspense of those instants as I fumbled anxiously for a shape in the dark blue.
At the same time I felt the desire and awe of preparing to face the biggest hunter on Earth: a marine mammal weighing about 40 tons and the size of a city bus.
I didnt have much time to think, however, before a huge adult female appeared a few metres away, swimming slowly in midwater. Disturbed by the clicks of my camera, she quickly turned and set her tail fluke against the water, pushing her gigantic mass into the depths with the nimbleness of a dolphin.
Getting more than a glimpse of these majestic leviathans under water is a rare privilege. I surfaced breathless, and Manuel came to collect me quickly.
There were four calves in the area, and another adult female. The calves were not yet able to undertake deep and extended dives and, to our joy, were less shy than adults and as curious as all mammal cubs.
At their age, sperm whales spend much of their time at the surface, waiting while their mothers and relatives feed on squid in the depths.
Adults stay under water for about an hour before having to come up for air. When the mothers return to the surface, calves are often seen breaching in welcome, looking forward to sucking their ration of milk.
That day, there were five different pods of sperm whale in the southern waters of Pico, the second-largest of the Azores islands. We were able to run to and fro all day observing different species of cetaceans, including Atlantic spotted and Rissos dolphins, the shyest dolphins I have ever seen.
The Azores archipelago, which sits in the middle of the Atlantic Ocean, nearly 900 miles from Portugal, is one of the worlds prime whale and dolphin hotspots. Nearly a third of the known cetaceans species have been observed here, close to the coast.
Sperm, pilot and false killer whales along with Atlantic spotted, striped, common, bottlenose and Rissos dolphins and a plethora of other marine life populate the waters around Pico.

THE AZORES PLAYS AN IMPORTANT ROLE in the marine eco-system of the North Atlantic. Its very complex oceanographic circulation is influenced by the Gulf Stream and branches of the North Atlantic and Azores currents.
Oceanographic features include steep submarine walls, ridges and escarpments and a very short continental shelf.
Combined with an upwelling of nutrient-rich deepwater currents against the steep walls of the islands, this is a relatively food-rich area in the nutrient-poor central North Atlantic. Providing food for a wide diversity of animals, both fish- and krill-eating species and those that forage on cephalopods, all the fish food-chain is well represented, from tiny micro-organisms to pelagic predators and marine mammals.
The Azores are a snack bar for cetaceans travelling between their feeding and breeding grounds. The bays and relatively shallow waters near the coast provide sheltered nursing grounds for whales and dolphins.
Despite the abundance of marine life, especially before stocks began to disappear because of over-fishing all over the world, in former centuries the Azores population dedicated itself to agriculture.
Whaling was introduced in the mid-1800s by sailors who had emigrated and then returned from the USA after years of experience on foreign whalers, but the Azores never really developed its own commercial whaling fleet - the whalers always sailed under foreign ensigns.
From the Vigia de Baleia, rocky towers built on the coasts, the vigia stayed from dawn to sunset at the mercy of strong winds, scanning the sea surface for the typical diagonal blow of the sperm whales. When one was spotted, the whaling crew would be alerted using loud fireworks and smoke-signals.
The hunters were farmers, workers or craftsmen who would stop work and launch their nimble wooden canoes.
A whale would be caught by flinging harpoons at its vital organs. Once it had stopped moving, it would be towed to the harbour, pulled up a slipway and transported to a factory.
In 1986, when Portugal joined the European Union, whaling was prohibited. Most of the islands still have small whale factories, and continue to organise rowing and sailing events using traditional whaling boats to commemorate the old whalers.

AS A DIRECT RESULT OF WHALING, the sperm whale is today on the endangered species list. Yet sperm whales still do not appear inclined to flee when humans approach them.
Today cetaceans find themselves the subject of a new brand of whale-watching. Tourism is highly important in protecting whales and dolphins, especially in small, remote and under- patrolled islands, but it needs to be carried out correctly, so that the animals are not disturbed.
We had an excellent experience with Pico Sport, a professional organisation managed by Frank Wirth, a great man deeply involved with marine life. Pico Sport is very safety-conscious, and shares its experience with many researchers and marine biologists.
It observes regulations formulated by the local government only in 1999, but also applies wisdom acquired through research and common sense.
Diving with sperm whales is normally forbidden in the Azores, and to obtain these pictures we needed special permits from its Environment Department.
But swimming with dolphins is allowed to almost everybody who has acquired the necessary permits.
Our thanks to Pico Sport - and to TAP Air Portugal for its help in loading our oversized and heavy luggage!

Pico Sport can arrange whale-watching, swimming with dolphins and diving and accommodation, www.whale-dolphins.net. TAP Air Portugal flies from the UK to Horta airport on Faial Island via Lisbon. The ferry to Pico takes 30 minutes. Spring/autumn is the best time to see female sperm whales and Rissos, bottlenose and common dolphins, April-June for seeing giant whales.

Looking for a pod of whales, though the weather looks unpromising
a whale surfaces to breathe and to examine the whale-watchers
a young whale investigates its appearance as reflected by the dome of the underwater camera.
A calf swims close to its mother, looking for a suck of nutrient milk and comfort while its mother surfaces to breathe.
An adult sperm whale plunges towards the abyss - they dive to 2000m or more.
The ancient art of scrimshaw - hunters used to carve or decorate sperm-whale teeth, like these preserved in the Azores.
In Azores waters, sperm whale calves are often alone and swim close to the surface. They need to breathe more than the adults, and cannot follow them on deep dives.
Sabrina Belloni
  • The sperm whales brain is the largest and heaviest known in any modern or extinct animal.
  • The head of a male takes up a third of body length.
  • Largest sound-producing organ in the animal kingdom - it can be heard five miles away.
  • Most highly developed social organisation of any great whale.
  • Largest toothed animal alive. Adult males average 42.5 tons and can exceed 18m in length.
  • Largest living carnivore.
  • Most sexually dimorphic cetacean. A mature male is more than three times heavier and longer than a mature female.
  • Lowest rate of reproduction among mammals, averaging one offspring.
  • Best mammalian diver. Dives of more than an hour to below 2000m have been recorded, but it is thought that a sperm whale can hold its breath for up to two hours.
  • Loudest animal in the world. Sperm whale clicks have a source level exceeding 230 decibels.
  • Extremely wide-ranging. Adult males can be found in every ocean, including the polar regions, though females and young stay in tropical and temperate waters.
  • Before commercial whaling, sperm whales consumed more biomass than the worlds entire fishing fleet.
  • A Nantucket museum contains the jawbone of a sperm whale measuring 5.5m.
  • The gullet is the largest among cetaceans - the only one large enough to swallow a human.