A ZONING system to separate snorkelling and scuba diving ''will come soon,'' the Phuket and Andaman coast dive industry heard at a seminar run by the Tourism Authority of Thailand on Thursday.

Quota systems to control the numbers of tourists and restrict the time they spent at coral reefs are also likely, about 100 dive firms and tour company representatives were told.

The seminar was called after the announcement of a surprise ban on select coral dive sites to allow Andaman reefs to recover from the damaging natural phenomenon of coral bleaching.

Authorities appear to have decided that the time has come for action at last on other fronts, too.

A vision of possible controls on Thailand diving industry came from the TAT's Attractions Promotion Director, Kulpramote Wanalert, who added that a summary of the sentiments expressed at the Khao Lak seminar would be passed on to Prime Minister Abhisit Vejjajiva.

It was hoped that standards set for the key diving sites at the Similans and Surin island, off the province of Phang Nga, north of Phuket, could set the standards for a proposed ''Green Resolution'' in Thailand's tourism.

Greater control and enforcement had to come, the meeting at the La Flora Resort and Spa Khao Lak was told, to protect Thailand's coral reefs.

As stakeholders, tour companies, boat operators and dive companies needed to band together to protect their common future, the meeting heard as it stretched across three-and-a-half hours.

While the bleaching of coral reefs has been the trigger for bans on dive sites within the marine national parks, the TAT clearly believes that much broader controls are needed to prevent deterioration of the quality of the diving experience in Thailand.

Under pressure to perform better will be snorkelling tour guides, generally considered to be poorly trained and incapable of preventing hordes of uninformed tourists from abusing the coral.

''There is a limit to what's called the carry capacity of the coral reefs,'' Khun Kulpramote said. ''This applies especially to snorkelling. We are looking at ways of spreading the load to different sites and to setting quotas and time limits.

''All this would require greater coordination and better training for everyone involved.''

However, she added that the controls could apply only within the national marine parks, leaving coral reefs outside the parks to cope with increasing numbers of sometimes ignorant tourists, with guides who did little to guard against reef damage.

She told the meeting: ''Don't misunderstand what we are saying. Some of you may be the problem, but you are also the solution.''

Thailand's one time position as the world's best diving destination was under pressure because of what was happening, she said, and the TAT had endeavored to broaden the region's attractions by promoting golf, spas, watersport, trekking and other activities.

Artificial reefs could help to take the pressure off popular dive sites outside the national parks, she said.

Kanakorn Limkroudet, owner of the Phuket-based White and Blue Harmony dive company, said that his firm had suffered about 40 swift cancellations in the wake of international media coverage of the restrictions placed on Andaman dive sites.

''Scuba and snorkelling do need different management,'' he said. Thailand's reefs remained among the best in the world and the scuba diving industry brought strong income to Thailand.

What was needed, though, was one organisations to take care of all the coral refs, he said. He highlighted the illegal fishing that had caused great damage.

''I always feel a sense of shame when I take tourists to a place where there are no fish to be seen,'' he said. ''Last year on a reef, we found a huge fishing net covering a large part of it. We did not know who to call, who to ask to come to cut it free.''

Phuket dive tour operators who protected the reefs and made sure their guests were careful were ''angry at the closures,'' he said, adding that it was ''time to enforce the law'' on illegal fishing around the reefs.

Sustainable diving tourism was the common aim, the meeting was told. Experts from Phuket's Marine Biology Centre and Marine Preservation Office detailed the reasons for the diving bans and the damage that had been caused by last year's unusually extended period of heat, which put large areas of coral at risk of never recovering unless they were left undisturbed.

Industry standards needed to be set, particularly for guides of non-English speaking snorkelling groups, and some of the sites that had already been damaged in ignorance needed to be given the chance to recover. There were alternative sites, the meeting heard.

But zoning, quotas, time limits and creation of artificial reefs probably represented the best options for the long-term future.

Among those at the meeting were the Director of the TAT, Southern Region, Poramet Amartayakul, and Phuket Regional Director, Bangornrat Shinaprayoon.