The old wreck, its scattered cannons encrusted with a heavy growth of coral, lies a mere 30 feet below the surface, in water so clear that the centuries-old tableau might as well have been encapsulated in lucite.

The size and shape of the heap of ballast stones vaguely suggest that it was a lightly rigged, wooden sailing ship, perhaps a Spanish caravel.

One hundred and fifty feet away lies the anchor, still set against the storm that sent the ship to a shallow, watery grave off the remote chain of islands known today as the Turks and Caicos.

The ship has no name. But an obscure 500-year-old tax report newly discovered in Spain suggests that the name it had may be as familiar as that of the Italian mapmaker who discovered the New World: It could be Pinta, one of the three ships that took part in Columbus' expedition in 1492.

Key West treasure hunters Olin Frick and John Gasque discovered the old wreck in 1977, while they were searching the waters of the Caicos Bank for ships to salvage.

Now, three years later, they believe that the wreck itself may be more precious than the gold and silver they were seeking.

The evidence is still tenuous and circumstantial. An iron cannon removed from the wreck appears to be the right age. A crudely formed lead cannon ball is vintage 15th Century. And some cryptic references to the location of the wreck in the Spanish archives suggest that the Pinta may have been one of the few ships in the area at the time the ship sank.

Next month, with financial support from Dallas millionaire William R. Reilly, the two treasure hunters and a crew of 23 divers and archeologists plan to return to the Turks and Caicos to recover the remains of the ship and any other artifacts.

"Like all archeological work, we may not be able to come up with absolute proof that it is the Pinta, but if we find nothing to contradict it, we think the weight of the evidence will be awfully convincing," says Gasque.

Agreement signed in September between their company, Caribbean Ventures Inc., and the government of Turks and Caicos, gives the men sole rights to salvage a number of 16th- and 17th-century shipwrecks in the islands, including some they believe will yield much gold and silver.

The government of the British-held islands will keep 30 percent.

The treasure hunters have relied heavily on the opinions of two experts, Mendel Peterson, former director of underwater archeology for the Smithsonian Institution, and Dr. Eugene Lyon, a Florida historian who specializes in research at Spain's Archives of the Indies in Seville.

Peterson, now an appraiser of shipwreck artifacts, says that he has "found nothing which would contradict" the treasure hunters' theory that they have located the Pinta.

A heavy iron cannon called a bombardetta, a lighter swivel gun and a single lead cannon ball removed from the wreck are all consistent with the period, Peterson says.

"Nothing is precisely datable, but nothing I saw could not have been in use at that time," he says.

Even if the ship is not the Pinta, but it is established that it sank around the turn of the 15th Century, it would qualify as the oldest shipwreck found in the New World.

"The ocean is like a huge pickle vat," said Peterson. "If conditions are right and something is protected from sea life, it will survive a long time in remarkable condition."