The seals use the ships' rudders as surrogate islands and have been known to hitch a ride into Newcastle harbour.

Nova Cruises general manager Peter Hanrahan spotted a pair enjoying a lazy start to spring off Newcastle yesterday.

Nova Cruises is one of the Newcastle and Port Stephens whale-watching businesses that is expecting a bumper season as whales, headed north and south, cross paths off Newcastle.

The National Parks and Wildlife Service estimates 10,000 humpback whales will migrate north to mate off the Queensland coast this year, double that of a decade ago, thanks to an end to whaling.

Mr Hanrahan said Nova was still seeing "stragglers" from Antarctic waters heading north but also the early birds, males and juveniles, returning south.

"This year the season seems to be three or four weeks ahead of itself," he said."

- Alison Branley