Law of the Sea runs aground amid 26 tiny coral isles

Nautical maps of the South China Sea display a warning - dangerous ground - across a scattering of 26 tiny isles that even a sea gull might pass up. These low reefs and heaps of coral, known as the Spratly Islands, are every bit as dangerous to political stability in Asia as they are to ship bottoms.

They are a potential Falklands to the region, sitting beside sea lanes vital to Japanese imports, and surrounded by rich fishing grounds and possible pools of oil and gas.

Seven countries plus Brunei (which becomes indepedent in 1984) circle the South China Sea. All but two - Indonesia and Brunei - have stuck flags on the Spratlys, claiming the political or economic territory that comes with it. Three have put troops there: Vietnam, the Philippines, and Taiwan. The Philippines has begun drilling for oil.

These tiny atolls lie in the eye of a political typhoon created by the Law of the Sea Treaty, completed this year. The disputed area is larger than Kampuchea (Cambodia). The pact left vague how nations would treat islands, especially ones that may be just rocks popping above the waves, and exactly how to carve up certain close-border waters. One lingering issue is whether a claim exists even if a cay disappears.

Even before the treaty took effect, nations had staked out 200-mile economic zones. The overlapping and crisscrossing claims around the South China Sea make a map of the area look like a Robert Motherwell painting. In one case, an exposed reef connects two Spratly Islands claimed by two nations.

''Almost all the questions left over from Law of the Sea are found in the South China Sea,'' says Dr. Mark Valencia, marine policy specialist at the East-West Center here.

The sea has a broad, shallow contintental shelf, surrounded by a number of small nations with big disputes, such as China and Taiwan, plus many historic mistrusts (Japan usd the Spratlys to invade the Philippines). In 1956, a Filipino tried to create a new nation called Freedomland out of a Spratly island , even going so far as to set up an ice factory and a nautical school.

Most of the surrounding nations of the sea are hungry for oil, which lies mainly offshore. China, the Soviet Union and the United States carefully guard this strategic conduit between the Pacific and the Indian Oceans. The US could potentially be called into a conflict if another nation challenged the Philippines' claim to the Spratlys. Added to all this is the possibility that submerged shoals could suddenly create new islands and new disputes.

Two of the world's largest archipelago nations abut the sea: Indonesia, with 13,667 islands spread across an area the size of the US, and the Philippines, with 7,100 islands. The treaty helps these nations gain better territorial - and thus political - unity by specifying both water and land between islands as part of the nation.

The disputed waters between Vietnam and China are the hottest. American and French oil rigs drilling in the Gulf of Tonkin under contracts ith China have been threatened by Hanoi. And with Soviet ships using former US bases at Da Nang and Cam Ranh Bay, a confrontation could draw in the big powers.

The potential for disputes is great, but so are the opportunities for trade-offs and cooperation in fishing, seabed mining, and drilling for oil and gas. The treaty was meant to encourage such cooperation. Thailand and Malaysia, for instance, agreed this year to sponsorjoint offshore oil exploration, setting aside a dispute in the Gulf of Thailand for 50 years. The Boeing Company has been combining the Southeast Asian nations in hopes of regional cooperation in setting up military and coastal surveillance - with Boeing aircraft. Indonesia has bought three Boeing 737s.

An atlas of potential resources in the South China Sea, and areas for possible cooperation, will be published this fall by the East-West Center, which is working with several countries to help understand the potential conflicts. Only in the last decade, for instance, did it become known that the Spratlys were not volcanic but part of a deep continent with potential hydrocarbons.

''The political situation is tense in the South China Sea,'' says Dr. Valencia. ''But politics can change, and a number of disputes can be resolved.''