KEY POINTS:
The parched Nullarbor Plain, a vast nothingness of salt-bush and stones which stretches for hundreds of kilometres across the southernmost strip of Australia, seems an unlikely place for whale-watching.
Nullarbor may sound like an Aboriginal word, but it's bad Latin for "no trees". The landscape around the lonely
Nullarbor Roadhouse lives up to that name. Not only are there no trees, there's barely a blade of grass in an area nearly the size of Victoria.
Blue sky arcs over the pancake-flat horizon and a lone wedgetailed eagle soars high.
But just 24km south of the isolated roadhouse, wildlife abounds. The desert abruptly ends where it meets the Head of Bight, the most northerly part of the great scimitar curve of coastline known as the Great Australian Bight.
Here the Bunda Cliffs, some reaching 80m, crumble into the sea like giant slabs of shortbread.
The bay, a stunning shade of turquoise, is crowded with big black blobs - southern right whales. As black and shiny as licorice, they congregate here between May and October.
They were hunted almost to extinction in the 19th century. Although the species is slowly recovering, the worldwide population is only about 4000. About 800 of the whales visit Australia, and the Head of Bight is one of the best places in the world to see these awesome creatures.
As many as 100 will gather close inshore, mating, giving birth and suckling their calves. So rich is whale milk that calves gain about 90kg a day.
They come here because the water of the Leeuwin Current is about 17C, relatively warm compared with their usual habitat in subantarctic waters.
Even from the wooden viewing platform at the top of the cliffs, the whales seem enormous. "An adult can be 17m long and weigh 70 tonnes," says tour guide Greg Limbert. "That's about the size of a road train."
Newborn calves are 5m and weigh 1 tonne. While their mothers are content to loll in the jade-coloured shallows, the youngsters slap their tails and indulge in a spectacular display of youthful exuberance.
They lift their heads above the water for a good look around and slam their tail flukes on the water in what's known as a tail lob.
An interpretative centre has been built just back from the cliffs to cater for the growing number of people who come to watch.
The roof is shaped like a whale and the walls are made of angled poles designed to represent the long baleen plates which crowd the mouth of a southern right whale.
"Last year we had 20,000 visitors," Limbert says. "It's becoming a destination in itself rather than just a stopover for people driving across the Nullarbor."
Researchers identify individual whales by the unique markings on their heads, known as callosities. The best-known whales have nicknames, such as Chip, Ned and Michelin Man.
The Great Australian Bight, which extends for 1100km, is one of the emptiest, driest stretches of coastline in the world.
Its endless surf-pummelled beaches, vast sand dunes, salt lakes and rocky headlands have an epic quality.
It was first charted by the British explorer Matthew Flinders. In the 1860s pioneers established pastoral runs on the Nullarbor, despite the crippling lack of rain. It was not until 1912 that the plain was crossed by a vehicle, and the road wasn't sealed until 1976.
The vast scale of the Nullarbor and Head of Bight is best appreciated from the air and scenic flights operate from a blinding-white dirt strip beside the Nullarbor roadhouse.
Strict rules mean that light aircraft must keep at least 300m above the sea, but that is low enough to provide a bird's-eye view of the cetaceans.
"From May to October it's pretty much guaranteed that you'll see whales," our pilot says as he dips the right wing of the aircraft to point out a mother and calf.
"Very rarely does a day go past when you don't see any. The record number seen in a day is 135."
Australian sea-lions live along this stretch of coast too, and great white sharks patrol the waters - the southern right whales' only predator, although only the calves are vulnerable.
In the unlikely event that you don't get some decent whale photos, there's a slightly tatty, almost life-size fibreglass whale outside the roadhouse. It looks surreal against the battered petrol bowsers and parked road trains.
A few hundred metres away is an even better photo opportunity - one of Australia's most-famous road signs, warning of the danger to motorists of passing camels, kangaroos and wombats.
The sign stands beside the arrow-straight Eyre Highway, which links South Australia with Western Australia and stretches into a shimmering silver haze.
Aside from the roadhouse, it's the tallest structure around in this region of sun-baked desert and ocean giants.
Whale Watching
* The whale-watching in South Australia season is May 1 to October 31.
* The Head of Bight Interpretive Centre is open from 8am to 5pm daily.
