Racing through cool, blue water astride a powerful machine. Wind in your hair, spray in your face, crashing through the waves at over 50 mph. It's an instant adrenalin rush and easy to think of James Bond, jet-skiing his way to a villain's island hide-out.

A glamorous picture of jet-skiing is not hard to paint and its appeal is growing around Irish shores but not - this summer at least - without some tragic consequences.

A Belfast man died in Sligo General Hospital last Tuesday week after he sustained serious injuries in a jet-ski accident at Mullaghmore the previous weekend. The jet-ski - or personal watercraft (PWC) - Glen O'Hare (19) was riding, which was also pulling a youth on water-skis, was in collision with another pleasure craft in Mullaghmore harbour.

The same weekend, Sabrina Gannon, from Ballybough, Dublin, died in a Malaga hospital after a crash in the Costa del Sol resort of Torremolinos when a jetski on which she was riding veered out of control. She suffered massive internal injuries. It was her first time on a jet-ski.

The dangers posed by jet-skis and fast powerboats are well documented, but measures to limit the menacing use of such craft have thus far evaded the authorities, who only seek to ensure their careful use in an otherwise regulatory-free environment. Although authorities and jet-ski fans agree that the root of the problem is caused by a minority, it is aggravated both by a lack of training and of policing.

To use or own a jet-ski or powerboat you need no licence, insurance or experience, yet the craft are potentially as dangerous as a 1200 cc motorcycle in untrained hands. In an effort to curb these dangers, new by-laws prohibiting their use in north Dublin coastal areas were introduced by Fingal County Council last month. Some beaches in the Fingal area - such as the Malahide estuary - were being overrun, with jet skis buzzing and circling around bathers.

It's an initiative that the Department of the Marine and Natural Resources wholeheartedly endorses, since the failure in many respects of legislation it implemented under the Merchant Shipping Act in 1992. The Department has circulated other county councils with the Fingal by-laws, urging authorities to consider similar measures around the coast to stem the careless use of PWCs in swimming spots.

Under the 1992 legislation, the Department had attempted to designate areas such as Lough Cara, Lough Owel and Carlingford harbour in Co Louth as jet-ski-free, but difficulties arose in the implementation of the Act because it did not provide scope for what local authorities sought to achieve - the protection of bathers in other areas. As a result, the Marine Institute is now reviewing the ways in which these craft can be most appropriately regulated. Meanwhile, an 11-point safety code was reissued by the Minister for the Marine, Michael Woods, in the wake of the recent tragedies.

But all these measures are in vain if - as the Minister admits - the individuals concerned do not practise common sense, or if resources are not committed to catching offenders in the act. A basic jet-ski is rated as having 60 hp, equivalent in motorcycle terms to a sports bike of 600 cc. On the roads, for good reason, a provisional driving licence limits learner drivers to 125 cc motorbikes (roughly 12 hp), yet in the licence-free world afloat you can buy a 135 hp jetski (and that's a popular model) and tear off round the coast without breaking as much as a voluntary safety code.

It's a ludicrous situation which has been tackled by many southern European countries only after incidents involving jet-skis led to loss of life or serious injury. Mediterranean states, where jet-ski use is far more prevalent, have clamped down with licensing and registration or, in some cases, complete bans.

The British government will legislate later this year so that county councils can curtail the mis-use of jet-skis which, according to reports to the British Marine Industry Federation (BMIF), have caused seven deaths in the last four years in Britain. Despite growing concern over these dangers, the BMIF says there is still only anecdotal reports of deaths and no hard statistics available on the extent of jet-ski injuries.

Already, a voluntary pilot data tag scheme is in operation in three English ports where a badge identifies each jet-skier and forces them to launch and operate in safe "play areas".

In Greece, after a series of tragic accidents, a ban on all jet-skis is expected from the Greek Supreme Court. In the meantime, there has been a considerable tightening of by-laws, according to Tim Donkin, Secretary-General of ICOMIA, the international marine organisation. Jet-skis cannot be used in built-up Greek resorts between 2 p.m. and 5 p.m. and all jet-ski riders must now hold valid driving permits. Jet-ski hirers are also obliged to fit the machines with an immobiliser, which can be operated remotely should a jetski get out of control.

A fatal accident in Ayia Napa, Cyprus, in which a jet-ski driven by a drunken Dutchman was in collision with that of a 32-year-old Southampton woman, killing her, also provoked swift reaction. A bill tightening legislation controlling jet-skis is before the Cypriot government, which aims to reduce the use of machines and ensure permits are issued before they can be hired.

While there are many lessons that we can learn from experiences abroad, there needs to be a willingness to comply with existing legislation at home to bring about a sea-change in the behaviour of many pleasure-craft users. And unless resources are allocated to back up the law, any new legislation will be of little value.

Paddy Boyd, secretary-general of the Irish Sailing Association (ISA), the country's biggest watersport organisation, has concluded that further fatalities are inevitable if high-speed PWCs continue to be used by untrained operators. Jet-skiing and powerboating are now widely regarded as two of the biggest growth areas in the marine leisure field and the Irish Marine Federation predicts that powerboating sales are set to double as more and more coastal and inland marinas are built.

Most tragedies occur because of inexperience or failure to observe safety regulations. But in a sport governed only by voluntary codes, enforcement is often difficult, in spite of the fact that these codes are there for the user's benefit.

The ISA represents some 20,000 sailors, and has an impeccable safety record, but has always relied on education rather than legislation for the preservation of its members. But those taking part in organised sailing races are quite different from those who opt for the brief use of a jet-ski on a summer Sunday. Educating the casual PWC owner, attracted more by the cool allure of the jet-ski set than the mundanity of a safety code, still remains a challenge for the association. Most jet-skiers appear to be outside the ISA's club system, and bringing them within the reach of the ISA's 30 regional teaching establishments could help make bays and harbours safer places.