Sydney - When whales become stranded on beaches in Australia, television pictures flash across the globe of volunteers with towels and buckets keeping the hapless creatures wet and trying to coax them back out to sea.

Sometimes, even before the tears of joy have dried, the once-rescued whales come in again and the heart-rending tableau commences anew.

In November, 65 pilot whales came ashore in Stanley, Tasmania. Volunteers managed to save 11 whales, keeping them alive while they were trucked 17 kilometres to a less shallow bay where they were released.

Pilot whales can grow up to 7 metres and can weigh 1.8 tons. They can dive to 1,000 metres and are very fast swimmers.

In a first for Australia, five of the 11 survivors were fitted with electronic tags so their getaway could be tracked by satellite. A day after their release, the 11 were together, swimming strongly and 40 kilometres from shore.

"Not only have they survived being put back in the water after their traumatic ordeal but they've also found each other and are travelling with each other," wildlife officer David Pemberton said. "For the first time in Australia, we've now got data which tells us that they're doing OK. It's fantastic and incredibly exciting."

There are more strandings in Tasmania than anywhere else in Australia because it has lots of shallow bays.

Opinions differ on why whales beach. Until now, there had been no evidence that the thousands of hours put in by hundreds of nature lovers were worthwhile.

David Pemberton, a zoologist at the Tasmanian Museum in Hobart, said stranding may occur while the mammals were feeding together or when they were driven onto the shore by an attack.