You can spot them by their binoculars, hooded jackets and gazes fixed on the horizon, watching intently for the flick of a dorsal fin or a sudden vertical spurt of water.

They are whale watchers, and the onset of winter next week heralds the start of their favourite season.

In what is fast shaping up to be an annual ritual for NSW coast dwellers, thousands of people are expected to take up lookout posts from Byron Bay to Eden this year to catch sight of migrating humpback whales.

A few of the whales, the so-called leaders of the pack, have already been spotted off the NSW coast.

The whales swim about 3000 nautical miles from Antarctica to the equator, occasionally delighting onlookers with dramatic blowing, breaching and tail-slapping.

Ronny Ling, president of the volunteer marine rescue organisation ORRCA, said he hoped sightings of humpbacks would improve this season. Although the usual number of whales, about 3000, made the journey north last year, they remained frustratingly far from the coastline to the disappointment of whale watchers.

National Parks and Wildlife Service (NPWS) figures show there were sightings of 520 humpbacks, 28 minke whales and one blue whale last year.

The year before, there were 932 humpback sightings.

"Last year sightings were significantly down," Mr Ling said.

"There is a lot of speculation why, but we think currents may have kept them further out from the shore."