It is a breathtaking and implausible sight. The sea seems to part suddenly and a vast creature, the size of a double-decker bus and more, hurls itself out of the water. For several seconds you take in its enormity as its moves through the air, and then it crashes down into the ocean, rapidly disappearing back to the depths. Exactly why a whale breaches remains a mystery, but the phenomenon constitutes one of the greatest thrills in wildlife watching.
Other encounters are wonderfully impressive: seeing a cloud of bubbles or a spout, watching a gigantic shape come to the surface of the water, witnessing a huge tail flipping out of the sea and then receding. Meanwhile there's a palpable feeling of joy in watching or being among a school of dolphins or shy porpoise. And a great sense of wonder, too, at these highly intelligent, highly communicative creatures.
Cetacean – the collective term for whales, dolphins and porpoises – derives from the Greek word for sea monster. These amazing mammals are peculiarly well adapted for aquatic life. They breathe near the surface of the water through blowholes at the tops of their heads; their forelimbs are flippers while their hind legs are tiny and hidden within their bodies; their tails are especially powerful thanks to two fin-like "flukes" at the end. The 80 or so species (the number keeps increasing as scientists learn more) are classified in two subgroups, essentially those with and those without teeth.
Odontocetes prey on fish and other game, so need teeth (the narwhal whale has a tusk). This group includes oceanic dolphins, river dolphins and porpoises as well as orcas (or killer whales) and deep-diving, large-brained sperm whales. Toothless baleen whales are gentle giants, filter-feeding on minuscule marine organisms and ranging in shape from humpback whales to prodigious blue whales, the largest animals ever to exist in the world – bigger, even, than the largest dinosaur.
Do I have to travel far to see them?
At this time of year, no. Indeed if you live near the coast you may find that you and your binoculars barely need to leave home. Dolphins in particular, but sometimes porpoises and whales, can be seen all around the shores of the UK – if you're lucky. In total, 28 species of cetacean have been recorded in British and Irish waters, the most frequent sightings being from boats, although seeing these sea mammals from land – particularly headlands – is by no means a rarity.
What's more, this week you can go whale and dolphin watching with real sense of purpose. The eighth annual National Whale and Dolphin Watch week runs from today until 26 July.
The survey is organised by the marine conservation charity Sea Watch (0845 202 3892; seawatchfoundation.org.uk) which is aiming to involve the public as much as possible in its efforts. Anyone can take part, either by going to specific sites and helping trained observers or by undertaking their own independent dolphin and whale watches and recording sightings on forms downloadable from the Sea Watch website, where species identification notes are also available.
The charity's dedicated watching areas are dotted around the country – Poole Bay in Dorset, Blackpool, Aberystwyth and Aberdeen being just some of the sites. Information about these and other locations as well as events and boat survey trips (for which a small fee is payable) is on the charity's website. The research gathered during the week's watch will help in assessing the distribution and numbers of sea mammals around our coasts and ultimately in forming conversation policies.
So where's best in Britain?
"Scotland probably offers the best viewing – and the greatest diversity," says Gemma Veneruso, sightings officer at Sea Watch. Off the west coast, fin and minke whales are fairly regularly seen, while orcas are not uncommon and Risso's, bottlenose and white-beaked dolphins are frequently sighted. Particularly rewarding viewing locations include areas around Cape Wrath, Red Point (south of Gairloch), Ardnamurchan Point and Mull.
Set up 25 years ago, Sea Life Surveys (01688 302916; sealifesurveys .com) is said to be Scotland's most experienced whale and dolphin watching operator and it provides a variety of trips from Mull, with options including a full-day "whale explorer" cruise.
Off Scotland's east coast, pilot whales, orcas, porpoises and various dolphin species are often seen. Hotspots include areas north of Eyemouth, the stretch of coast between Dundee and Aberdeen, and most of all, the Moray Firth where there is a resident population of about 130 bottlenose dolphins. Among those offering sea trips in the locality is Ecoventures (01381 600323; ecoventures.co.uk) based at Cromarty.
Another notable population of bottlenose dolphins is resident in Cardigan Bay in west Wales. Trips around the bay to see not only dolphins but also harbour porpoises and grey seals are provided by New Quay Boat Trips (01545 560800; newquayboattrips.co.uk) from New Quay harbour.
And getting warmer?
While most whale watching in Europe is a summer activity (generally between May and October), the Canary Islands offer year-round viewing. Bottlenose dolphins and at least 400 pilot whales are resident in an area just south of Tenerife while beaked and sperm whales can also be seen in these waters. One of the most established operators here is the Nostramo Group (00 34 922 750085; tenerifedolphin.com) offering trips from Puerto Colon in a glass-bottomed catamaran (booking is essential). Or head to Tarifa on the tip of mainland Spain from where bottlenose and striped dolphins can be sighted year-round in the Straits of Gibraltar, while sperm whales – and sometimes orcas – are summer visitors. Among those arranging spring and summer boat trips is Whale Watch Tarifa (00 34 639 476 544; whalewatchtarifa.net), a branch of the educational association Whale Watch España.
Better still is the prime whale-watching outpost of Portugal, theV CAzores archipelago in the Atlantic – almost midway between Europe and America. Between April and September, the waters around these green, much-rained-on islands attract a fabulous variety of cetaceans, from massive blue whales to orcas and spotted and striped dolphins. You may be lucky enough to see some species from the land, but a better bet is join a boat trip – there are a number of operators at Horta Harbour including Peter Café Sport (00 351 292 292327; petercafesport.com). Or sign up for a seven-day catamaran adventure with Whale Watch Azores (00 351 96 527 4312; whalewatchazores.com), which combines tourism with serious research.
Iceland is northern Europe's greatest haven for whales – and whale watchers. Orcas, blue whales, minke, fin and humpback whales, white-beaked dolphin, harbour porpoises and more are regularly seen between May and October in the waters here. There are numerous whale-watching outfits dotted around the coast. You can even step off the plane and join a boat trip. The Whale and Dolphin Spotting company (00 354 421 7777; dolphin.is) runs three-hour excursions from Keflavik harbour, five minutes from the airport. But for a real treat head to Husavik in the north east. Here you can immerse yourself in whale culture, from natural history to art, at the Husavik Whale Centre (open daily June to September; 00 354 414 2800; whalemuseum.is) and then take a boat trip with North Sailing (00 354 464 7272; northsailing.is) on whose tours 73 blue whales and 484 humpbacks were spotted last summer.
Norway also presents excellent whale-watching opportunities, with a backdrop of spectacularly beautiful fjord country. Head to the harbour at pretty Andenes in the north to join a summer excursion with Whale Safari (00 47 76 11 56 00; whalesafari.com) on which you are almost guaranteed to see sperm whales and possibly orcas and minke whales too.
A few kilometres further south, Tysefjord offers the prospect of some stunning winter whale watching. Between November and February the waters here provide winter feeding for quantities of herring (although numbers have recently declined slightly). The fish are pursued by orcas, and also by white-tailed eagles.
Orca Tysefjord arranges winter orca-watching trips on big boats and inflatable dinghies from Bognes; you can find out more and make bookings through the Tysfjord tourist centre, 00 47 75 77 53 70; tysefjord-turistsenter.no).
Can I go further afield?
For superb whale watching without leaving dry land, make for Walker Bay on the Western Cape of South Africa. Here the cliffs around the town of Hermanus provide amazing vantage points for spotting Southern Right whales – particularly during the calving season, between July and December. These slow-swimming plankton-feeding cetaceans have been known to come within 5 metres of the shore (more information on hermanus.com/ whalewatching.mv).
Alaska presents surprisingly accessible nature watching, about three hours' drive from Anchorage. The Kenai Peninsula is a thumb of land slightly bigger than Belgium that dangles into the Gulf of Alaska and offers stupendous sea sights off the fjords of its eastern side. In spring and summer, take a day's boat excursion from the bustling harbour town of Seward and you are almost bound to see orcas and humpback whales – as well as puffins, sea lions and seals. Trips are arranged by Kenai Fjords Tours (00 1 877 777 4051; kenaifjords.com).
Or head to Cape Cod, whose waters are a summer feeding area for humpbacks – who sensibly spend their winters in the Caribbean. Until the end of October, two daily whale-watching boat trips are offered by Hyannis Whale Watcher Cruises (00 1 508 362 6088; whales.net), leaving from Barnstable Harbor.
Among the world's other prime destinations for whale watching is Kaikoura on New Zealand's South Island. Due to a collision of currents in the waters here there is an abundance of food for sperm whales, which can be seen all year round. And that's by no means all: pilot, humpback, blue and southern right whales are also known to frequent the area. In addition, Kaikoura attracts enormous quantities of seabirds, including 14 types of petrel. Boat tours are arranged by Whale Watch Kaikoura (00 64 3319 6767; whalewatch.co.nz) owned and run by indigenous Kati Kuri Maoris.
What about river life?
There are currently known to be three species of river dolphin – small, moving like quick-silver and very tricky to see. The pink boto dolphin lives in South America and is most populous in the Amazon and its tributaries. Meanwhile the Franciscana dolphin lives in the estuaries on the south-eastern coast of South America. The Ganges and Indus dolphin is primarily found in the Ganges and Brahmaputra rivers of India. Fortunately you have a very good chance of seeing these rare creatures on cruises along a stretch of the Brahmaputra in Assam – but you have to look hard: the dolphins arch out of the water and disappear back again in an instant, a tiny blur of a brown curve with a long snout. The trips are run by Assam Bengal Navigation, with offices in Guwahati and in Rutland (01572 821121; assambengalnavigation.com).
Until recently there was a fourth species. But in August 2007 China's Yangtze river dolphin, also known as the baiji, was declared extinct. Scientists cited human activities, from electrofishing to the construction of dams, as the cause.
And remote adventure?
Several British tour operators offer dedicated whale-watching holidays in out-of-the-way destinations. Out of the Blue (0845 290 3218; oceansworldwide.co.uk), for example, specialises in whale and dolphin trips anywhere from the Shetland Islands to Alaska and Kamchatka, in Russia. The company is affiliated to the Whale & Dolphin Conservation Society (01249 449500; wdcs.org.uk) to which it makes a donation for every booking taken. One of its most intriguing ventures is a trip to Patagonia to see orcas, southern right whales, sea lions, glaciers and more. The 13-night holiday departs 1 November and costs from £3,500 per person (based on two sharing), which includes flights to Buenos Aires from Heathrow, onward domestic flights and ground transport, accommodation, wildlife trips, guidance and some meals.
In the northern hemisphere, Discover the World (01737 218 800; discover-the-world.co.uk) offers a trip to remote reaches of Newfoundland. Humpback whales are very frequently sighted here and you may even see them lunge feeding on the beach. Other wildlife encounters may well include puffins, seals and moose. With departures until the end of August, the eight-night holiday costs from £2,350 per person (based on two sharing), which covers flights from Heathrow via Halifax to St John's, accommodation, ground and sea transport, entry fees, guidance and some meals.
Carnage to conservation
Save the Whale: the high-profile campaign of the 1970s drew attention to commercial whaling and its disastrous results for the world's cetacean population – the humpback whale, for example, was teetering on extinction. In 1986 a moratorium on commercial whaling came into effect and since then numbers have improved, although several species – such as the blue whale, the narwhal whale and the North Atlantic right whale – are classified as endangered by the World Conservation Union ( iucnredlist.org).
The rapid growth of whale watching has strengthened public awareness of the need for conservation. Just 20 years ago, for instance, Iceland was still a significant whaling centre. The first whale watching ventures started there in 1995 and now Iceland is among the world's leaders in marine tourism. (It is, though, considering a resumption of commercial whale hunting. Meanwhile Japan has for years flouted the moratorium.)
Vanessa Williams-Grey, whale watching programmes manager at the Whale and Dolphin Conservation Society, encourages us to see the great mammals of seas but she acknowledges that in some instances whale watching has become a victim of its own success. Some operators, she says, try to cash in on reliable whale-sighting areas, leading to overcrowding that can frighten and displace animals from their preferred habitats. And she warns against encroaching too much on whales and dolphins. Many people want to swim with these mammals but, she says, "They are wild animals that deserve space and privacy."