Scotland's simmering dinghy racing renaissance crests a new peak today as Dalgety Bay Sailing Club hosts the national Audi Laser quattro Cup for the first time.

With over 65 boats set to converge on the bustling Forth venue the four round nationwide regatta series, which features the Laser 5000 and the Laser 4000 classes, descends on Scottish waters for the first time.

Fuelled by the car company's ongoing support the two classes have cornered the lion's share of the market in close exciting dinghy racing thanks to new design

innovations which have simplified sail handling and equalised the

differing crew weights.

With a massive 30 square metre asymmetric spinnaker as the downwind turbo, the bigger 5 metre long twin trapeze 5000 is much more of a handful than the 4000 and has become the domain of many of the country's leading sailors. The requirements are for a heavier all up crew weight and while the 4000 at 4.64 metres long is marginally slower with a 17.1 square metre spinnaker, it has proven attractive to couples who put their harmony to the test around the race course.

While dinghy racing was once a plod around a big pond, the recent packaging of the sport for TV has driven this class, and others, to develop short sharp easily understood races. The races last at most 50 minutes and are straightforward laps upwind and downwind round two markers. Three such races will be sailed today, and three more tomorrow.

The other crucial ingredient which the Audi sponsorship has brought is the chance to build up the evening social events. The sail hard party hard ethos is a crucial part of the successful mix.

Audi support three circuits for the Laser marque, the Audi Laser EuroCup - a three event tour which started in April in L'Orient, Brittany, moves to Hayling Island on the south coast of England in July and reaches the final leg on Italy's Lake Garda in September.

The quattro Cup is UK-wide and aggregates the best three overall results from the four regattas - after Dalgety Bay there are events at Plymouth, Grafham Water in Cambridgeshire, and Warsash near Southampton.

In Scotland only there is the Audi Grand Prix series which is raced from Dalgety Bay.

The Scottish crews - now 30 in the 50-boat 4000 fleet this weekend and four-strong in the 5000 pack - hope to win both classes, and there's no reason why they shouldn't.

In the final phase of the quattro Cup last year Scottish boats took four of the top eight places, and any one of five Scottish teams have the potential to win races this weekend. So tight is the racing however that there is an equal opportunity to plumb the depths of the fleet.

''Racing is so tight and so close and tactical that you just don't have a second's respite. The action is coming at you all the time and you're always looking to defend your positions. It is very easy to lose a lot of places on the downwind legs,'' remarked David Bain a former European champion and Scottish Champion of Champions winner.

Bain, who like many others in the vanguard of the 4000 class in Scotland has been drawn from the front ranks of many other dinghy classes, sails with his wife Wendy. Along with Ian and Carol Calder who are supported by marine fittings company Holt, ex-pat Kiwis Pete Nicholas and Lisa Edreira (Adobe), Sandy McPhail and Andy Marshall (Yachting Life magazine) - all from the home club, and the Tay's Pete Hay and Richard Harper, are all potential race winners who by composing a series of consistent results could win the regatta.

They are very much on form.

In the Laser 5000 class Scots brothers Andy and Dave Richards swapped from the Olympic 470 class three years ago and finished seventh overall in the European series last year.

Now equipped with a new boat and sails, they dominated the first EuroCup event sailing their boat Brut Aquatonic in L'Orient until the last day when they came off worst from a pile-up at a turning mark, and last weekend they won the Laser 5000 UK series at Draycote Water with a race to spare.

The brothers test the lower limits of the crew weight equalisation systems, found in both classes, as they weigh in at the lightest end of the scale, 135 kilos, all up, which means they have the racks they trapeze off set at the widest possible, and their boat carries 35 kilos of weight to bring them up to the nominal 170 kilos.

''Our light weight has proven no disadvantage in any particular conditions,'' said Andy.

''In France we were very quick when it was windy and we were just as good when it was light winds.''

While the Scots will be pulling out all the stops for a home double, the club itself will be aiming for a polished regatta management performance too, as Scotland has been awarded the Laser 4000 UK championships for the year 2000.