EVER-INCREASING traffic on an ever-decreasing harbour has sparked a Marine Department investigation into further regulating the pace of high-speed craft around Hongkong. The Deputy Director of Marine, Mr Ian Dale, said yesterday it was clear that more and more high-speed vessels, such as jetfoils and catamarans, would be using the harbour in future and could pose dangers if left unchecked. ''We are looking at it in some detail now, especially the speed of ferries in the harbour area,'' Mr Dale said. ''We've got a lot more craft around the airport now as work there starts to build up, but we're far from any decisions yet.'' At present 74 of the 118 high-speed craft using the harbour, some capable of more than 35 knots, are granted exemptions from normal in-harbour speed restrictions. Forty-three, including the Far East Jetfoils serving Macau, are allowed to waive restrictions during day and night. Some exemptions could be scrapped following the review. The news follows a weekend accident in which seven people were injured when one of the exempted ferries, China-owned high-speed catamaran Tai Ping, collided with a local fishing boat on its way to Taiping in Guangxi province. Investigations are still continuing. Mr Dale said the review had been sparked by wider issues rather than specific accidents, some of which could be put down to poor visibility. Accident figures, many put down to the mooring of ships, jumped by 25 per cent last year from 255 in 1991 to 321 last year. Harbour traffic is increasing each year, fuelled largely by booming Pearl River traffic, now up to an estimated 120,000 vessels annually, while the waterways shrink due to reclamation. The review also follows the introduction this year of specific licences for the master, chief officer and engineer of high-speed craft, according to different makes and models, recognising the special skills needed. Assistant Director, Mr John Tse Yan-chi, said controlling a high-speed vessel was far more active than sailing a slower ship, with split-second decisions needed on information from the radar and electronic controls. ''It's more like driving a car,'' Mr Tse said. ''Everything happens so much quicker and a great deal of skill is needed.'' Sources said industry officials are likely to resist further regulation, with current exemptions giving high-speed craft the edge on such runs to places like Macau and the burgeoning Pearl River trade. Mr Tse said it was not just the exemptions being looked at, but the whole impact of high-speed craft on the harbour. He said they had to consider the effect of waves produced by high-speed wakes around anchorages, sea-walls and cargo working areas. ''Just imagine what could happen to a 40-tonne container on the end of the mast of small cargo vessel working at a sea-wall.'' He added: ''We are looking to take a very pro-active approach, recognising the needs of industry and the public.'' Among the first affected by any change would be the Hongkong Ferry Company, (HKF) who have just placed a $70 million order for two high-speed 449-passenger catamarans, the first of what could be several for the Central to Tuen Mun route. The company are hoping to shave about 30 minutes - half the time - off current services. HKF president Mr Peter Wong Man-kong, said yesterday he was keen to talk further with officials to ensure agreements were reached to the benefit of all. ''We have recognised the need for high-speed ferries, but would support standards for regulation and monitoring and want to work closely with the Marine Department on these issues,'' he said.