A black-hulled boat bobs silently on the aquamarine waters of Port Vila's harbour in the tropical paradise of Vanuatu, a thatched roof perched on top like a straw hat.

Nearby, brightly coloured jet skis are neatly lined up, inviting people to ride into the sunshine under a clear blue sky.

The picture-perfect scene of Vanuatu has only one element missing -- tourists.

Visitors have poured out of the country on commercial and military flights since Cyclone Pam stuck on Friday night, with electricity yet to be restored to many parts of the capital and numerous hotels, including top-end accommodation such as the Holiday Inn, shut for repairs.

The tourism sector has ground to a halt in Vanuatu, with local operators worried that by the time visitors return to the island archipelago, many workers will have lost their jobs and livelihoods.

"We've had no tourists since the cyclone hit us," said Bob Bebe, the manager of U-Power Sea Adventures as he stood beside the boats.

"It's really affecting the tourism industry. Most of the businesses are closed now and I think a few of them will close down (permanently), especially those on the water."

Bebe's company usually has a staff of five, but since the cyclone swept through Port Vila on Friday night, leaving a trail of destruction, only two remain to tend the boats.

Tourism accounts for an estimated 40 percent of Vanuatu's economy, with one-third of the approximately 267,000-strong population formally employed in the sector, according to Australian government estimates.

With the country reliant on Australian and New Zealand aid to survive, a sharp fall-off in visitors to the island nation -- which is marketed to tourists as an unspoilt and remote paradise -- is a key concern for the government.

"It's going to have a massive impact on tourism. It's the biggest income earner for the country," Vanuatu's Lands Minister Ralph Regenvanu told AFP.

"At the moment we are still in response mode, so just trying to make sure people have clean water and shelter and medical supplies. Once we stabilise that situation, then we have to start thinking about how we get the economy back, including tourism."

- Cruise ships divert -

Regenvanu said as Vanuatu did not have a welfare system, the government was looking to support cyclone-affected businesses and communities through measures such as providing construction materials and equipment, and paying for school fees.

The government was already working to restore marine navigation systems that went down during the storm, he added.

Some cruise companies have diverted their boats away from Vanuatu, with several expected to dock at neighbouring New Caledonia instead.

The international cruise industry is a growing money-spinner for the sprawling archipelago.

Around one ship docks at the nation's ports every day, bringing thousands of tourists, Regenvanu said.

Merilou Niederer, 30, a receptionist at the Coconut Palms Resort in Port Vila, said she was relieved to still have a job as many others were without work after scores of hotels damaged by the storm temporarily closed.

The resort is one of the few in Port Vila with power.

"Most of the companies -- hotels and resorts -- are closing down," Niederer said.

"(Staff) will have to stay at home and lose their jobs. It worries me a lot as they have to feed their families."

Australians Mike and Dawn Jones, among the few tourists who did not leave the country immediately after the cyclone hit, said they decided to keep the same departure date and stay on in Port Vila despite the lack of essential services.

"We'll definitely be back, we love this place," Mike Jones, 69, said as he left the resort ahead of his flight home to Brisbane on Australia's east coast.

"(The staff) looked after us the best they could."