Last year, the gambling haven attracted more than 6.72 million Hong Kong visitors. Given that boats are still the main transport link between Hong Kong and the former Portuguese enclave and a return ferry ticket costs about HK$300, the service is a multimillion-dollar business.

In contrast, local ferry services on outlying island routes have been struggling on a dwindling patronage and running at a deficit.

A captain of a Macau ferry line not only earns more than double his counterpart on local routes, but the experience in the Pearl River estuary means more job options.

First Ferry, which runs both local and Macau services, says it has little difficulty in recruitment. 'The response to recruitment adverts of our local lines may be less enthusiastic as compared to the past, but our turnover rate is so low we don't have problems filling the vacancies,' said Anthea Chan Shuk-man, the corporate communications manager of First Ferry.

Years ago, most people entering the ferry business were boat fishermen who joined the trade in their 20s and stayed. Now they are getting old.

Nelson Ng Siu-yuen, the general manager of Hong Kong and Kowloon Ferry, which operates half of the city's six outlying island routes, said the average age of his staff had changed from 40-something a decade ago to 50-something in recent years. 'In the long run there could be a succession problem,' he said.

Ng said one of the reasons was a lack of promotion. A sailor could be promoted to a coxswain, then earn more or less the same wage for the rest of his career.

First Ferry coxswain Ng Muk-kam, who has been steering a vessel for more than 30 years, said fresh graduates who joined the industry did not stay. 'They work hard and are very eager to learn, and then they leave, sometimes in a few months.'

Coxswains on local ferry lines can earn up to HK$14,000 a month. They sleep and eat on the vessel and work alternate days.