FOR this year's celebration of Bastille Day in Hongkong, the Consul General of France, Laurent Aublain, will host a traditional French-style cocktail party for the French community at the Lycee Francais. At the end of his speech, the first verses of Rouget de Lisle's Marseillaise, will be sung to emphasise the patriotic fervour of July 14. Mr Aublain said the cocktail party would be the highlight of French National Day. However, French comrades would gather throughout the day, for luncheons such as one organised at Au Trou Normand by the Union des Francais a l'Etranger. So, how will their celebration differ from the French festivities back home? ''Although there are some basic French traditions that the entire country takes part in, celebrations vary according to the region,'' said Philippe Buchel, a member of the French Business Association. Frederic Grisier, director of Samco, recalled a typical National Day celebration of his childhood. ''Every year, all the children of our village paraded in costumes in the torchlight procession,'' he said. Those who spend the 14th in Paris were showered with a fete de magique. ''Even when you don't live in Paris, you still try to watch the magnificent fireworks and military parade on the Champs Elysees,'' said Luc Fayolle, director for the French Trade Commission. French are renowned for their vacationing habits during this time of year. ''French love to spend the 14th away at their summer homes on the Riviera or in their country homes,'' said Thierry Leleu, a French attorney in Hongkong. ''Because it always falls during school vacation, my whole family and many of our cousins will go sailing. ''Lounging on our sailboat off the coast of southern France, we'd watch the fireworks light up the black summer sky and pop open a bottle of champagne.''