“It’s an open secret among us that these are guest houses on water because the houseboats never sail but remain permanently moored at the same place,” said Dong, who has been looking after a powerboat at the typhoon shelter for the past two years.

A controversy over the use of houseboats as guest houses or Airbnb accommodation on water was ignited this week when lawmakers and a hotelier group accused the Transport and Housing Bureau of not doing enough to stop what they described as a rampant illegal business.

They said the current maximum penalty of a HK$10,000 (US$1,274) fine was too little and the number of prosecutions, too low. They wanted the rules tightened to protect legal businesses, and serious law enforcement to ensure a level playing field.

The bureau said it initiated 27 prosecutions related to the illegal use of leisure boats over the past five years, including eight involving the use of vessels as guest houses.

It acknowledged companies were advertising their illegal services on the internet.

Under the Merchant Shipping (Local Vessels) (Certification and Licensing) Regulation, pleasure boats such as yachts, cruisers and open cruisers can only be used for leisure purposes, such as water sports and going out to sea.

If a boat is used for residential purposes, the owner, his agent and the coxswain – the person helming the vessel – may be fined up to HK$10,000 each.

Steven Ho Chun-yin, a lawmaker representing the agriculture and fisheries sector, said: “The fine is so mild that it can be covered by a few deals, that’s why we need a more deterrent penalty.”

The bureau said the Marine Department was in the midst of prosecuting the owners of two leisure boats suspected of being used as guest houses in the Aberdeen and Shau Kei Wan typhoon shelters last December. They were found out during an undercover operation.

Michael Li Hon-shing, executive director of the Federation of Hotel Owners, which represents most of the city’s hotels, accused authorities of doing too little to enforce the law.

“The situation is so rampant yet the number of prosecutions is so low and the penalty is too little,” he said.

Although the federation had raised the issue for years, he said, complaints had fallen on deaf ears. He added that using leisure boats as lodgings was unfair to hoteliers, who were subject to rules.

“How come the equivalent of Airbnb on leisure boats is allowed?” he asked.

Lawmaker Ho said he was told that at least 10 leisure boats at the Aberdeen typhoon shelter and three more at Shau Kei Wan typhoon shelter offered staycations at a minimum of HK$2,000 a night.

“These operators are using public resources to make a profit, and when there is a typhoon, some boats may not be able to moor at the shelter,” he said.

All local vessels are allowed to enter the typhoon shelters for refuge when necessary.

Ho said fishermen had complained to him that three cases of fire involving boats at the two typhoon shelters were related to vessels offering staycation services.

“They were a fire hazard to the many fishermen’s boats in the typhoon shelter as they are so close to each other,” Ho said.

One company is known to advertise online, offering about five houseboats for minimum rental periods of 18 hours, charging at least HK$4,690 for three to five people at a time. Guests who embark between 2pm and 6pm must leave by 11am the next day.

Most of its houseboats are moored at Aberdeen. Although the company touted the beautiful surroundings as an escape from the city, it added a disclaimer that it did not offer accommodation.

Ho scoffed at that, saying: “This is like someone is selling heroin, but saying it is not heroin.”

*Name changed at the interviewee’s request.