AFTER four years of high growth, Thailand's golf course business has hit the rough in a big way, blown off course by rising costs and over-optimistic demand. With 200 courses under construction or already open for a fairly modest golfing population, the only score now being kept is on the number of pending bankruptcies. ''There will be many clubs in trouble in Thailand when the banks start calling in their loans,'' said one prominent real estate agent. ''Golf courses need strong patronage, and the game hasn't grown fast enough to accommodate them all.'' Golf became fashionable as a game and - even more - as an investment in Thailand on the back of the 1987-90 economic surge, which brought in thousands of Asian executives. A handful of promising local golfers emerged, prompting an injection of overseas sponsorship that boosted Thailand's claim to regional status in the sport. Tour packages were developed for the Japanese, offering an air ticket, hotel and temporary membership for less than the price of a round of golf in Tokyo. The early Bangkok clubs, easily accessible to the main golfing population and importing experienced overseas management, flourished with full memberships. But when developers started moving out to the more remote provinces, paying huge vanity fees to Greg Norman and Jack Nicklaus to create green fields in the middle of the rice paddies and abandoned quarries, the industry began to confront some basic economic realities. ''There are 12 golf courses planned for Kanchanaburi: you'd be lucky to find 12 golfers in Kanchanaburi,'' said Mr Simon Edmunds, a golf marketing expert. Few of the developers who rushed into the industry in the late 1980s had any experience with golf courses. Expertise and materials, including grass suitable for a humid climate, has had to be imported at great cost from abroad. Potential investors had little legal protection for their money. Projects used membership payments to fund land purchases and guarantee bank loans. When the money ran out, many projects were delayed or simply failed to materialise. In some resort areas, notably Phuket and Pattaya, owners have had clashes with the farming and environmental lobbies over the heavy demand for water, already scarce from Thailand's worst drought for a century. Mahidol University, in Bangkok, estimates that the average course consumes 480 acres of land and 6,500 cubic metres of water daily - three times the watering needed for an entire crop of rice and enough to support 6,000 urban dwellers. ''This is not development we are talking about, but resource exploitation,'' commented The Nation, a Thai newspaper, in a recent editorial. ''Our land simply cannot support the construction of more courses to satisfy the falsely green fantasies of thousands of foreigners.'' The overseas demand that was supposed to keep golf courses afloat petered out with the economic downturn and a slump in tourism arrivals. China is now luring the Chinese and foreign expatriate debenture markets, though local corporations continue to buy courtesy memberships for executives. Thailand itself has 400,000 golfers, but only about 20 per cent are considered wealthy enough to join clubs. ''We estimate that the people who have the money to buy is about 50,000 golfers only,'' said golf exchange director Mr Parichote Sukriket. ''And if you look at the number of memberships that they have sold to the market, it is about the same amount. ''The middle classes, who may earn less than 15,000 baht [about HK$4,600] a month, cannot afford the weekend fees, which cost about 1,500 baht for a game.'' However, he said falling club prices would create a new market once investors began to bail out. ''Since the prices are now coming down, the real golfers who have the money and find it worthwhile to have a membership are starting to come in.'' With an estimated 85 per cent of all Thai golfers living in Bangkok, clubs in provincial Pattaya, Phuket and other resorts face a tough time surviving. Developers at more remote courses have been forced to include hotels, holiday homes, riding schools and artificial lakes in projects, adding to soaring overheads.