DUBAI, UNITED ARAB EMIRATES, OCT. 6 -- A Gulf Air passenger jet was inbound at 10,000 feet to Sharjah International Airport last week when its captain received a surprising query from a stern American voice on his radio headset:

"Unidentified aircraft bearing one-one-eight degrees this is a U.S. warship . . . . Your intentions are unclear. Please identify yourself and state your intentions."

A British-accented air traffic controller broke in to announce that the plane was a civilian passenger jet, but the warship went right on with its challenges.

The air traffic controller lost his patience. "U.S. warship, you are posing a hazard to civilian aviation."

Undeterred, the U.S. Navy vessel a few minutes later challenged Pakistan International Airways flight 282 flying at 33,000 feet en route from Qatar to Karachi.

Again, the exasperated controller replied: "U.S. warship, are you going to be doing this for the rest of the day?"

"That's affirmative, sir," the American voice replied.

"Well, then I suggest that you please get your ship commander to contact the U.S. Embassy in the U.A.E. and sort this one out," the controller said.

There is a war going on here. To the north, it is being fought on land between artillery gunners and infantry, and offshore between antiship rockets and unarmed oil tankers. This conflict between Iran and Iraq takes place mostly out of sight of the western press, and partly for that reason had been largely ignored until recently.

But freshly encamped U.S. media organizations have discovered a new method for eavesdropping on the seven-year-old conflict. They have tuned in with radio scanners, listening in on the battle zone for the cries of oil tanker captains under attack and western navies trying to cope with mine threats, guerrilla-warfare speedboats and frightened merchant seamen.

Like the citizens-band radio mania that tied American highways into electronic knots a decade ago, marine radio communications in the Persian Gulf, where war mixes freely with commerce, are drowning in a cacophony of electronic banter and bluster.

With the arrival in the region of nearly 100 warships from the world's maritime powers and following a series of violent episodes since the Iraqi warplane attack on the USS Stark in May, the once routine chatter between ship and shore, plane and tower is now regularly broken up by chilling verbal clashes.

This is a war being fought in large measure on the radio, and to participate, the only weapon needed is a marine-band VHF set.

In the past week, normal radio conversations concerning such mundane transactions as ship supplies, requests to enter port and weather reports have been interrupted by the following tense exchanges:Monday, near the Strait of Hormuz, a Danish container ship, the Chastine Maersk, attempted to bypass an Iranian warship interrogating a group of Japanese tankers leaving the gulf. The Iranian burst out over the radio ordering the Danish ship to stop: "I warn you, I warn you, I'll have to take action. This is your last warning."Off Dubai last week, an Iranian and a Soviet warship were monitoring each other when the Iranian threatened, "Soviet warship 905, this is Iranian warship. Your director {radar} is {pointed} toward us. Switch off your director, this is your last call."Saturday, as a U.S. warship was returning to the gulf after escorting an American-flagged Kuwaiti tanker to safety, an Iranian warship appeared on the horizon.

"Iranian warship, this is a U.S. warship. You have locked your fire-control radar on a U.S. warship. Secure it immediately. This is your only warning."

A Pentagon spokesman characterized this last confrontation as "routine harassment" that U.S. warships meet in the tense environment of the gulf.

But many such encounters also appear to approach a hair-trigger threshold, the kind that the captain and crew of USS Stark shied away from until it was too late to defend against Exocet missiles that struck the ship and killed 37 Americans.

Though many Arab state officials here profess to feel more secure with the western navies patrolling these waters, some recognize the danger of a miscalculation.

"The greatest danger is somebody making a false move, something which is misinterpreted," said Bahrain's Minister of Information Tariq Moayyed last week.

The close encounters on the radio waves are tense enough, but the tension is often exacerbated by the clutter of overlaying radio messages on the main maritime hailing frequency. Warnings are often lost in the noise of other radio operators who mistakenly interrupt or just ignore the international protocols of taking turns on the air.

Worse, according to shipping executives here, are the mischief makers, the most notorious of whom is known as the "Filipino Monkey," who squeals his moniker and abusive language, mostly barnyard noises and obscene taunts, over the marine channels at night.

His irritating performances have spawned various imitators.

In one episode this summer, an Iranian gunboat halted a container vessel entering the gulf and demanded to know its cargo.

Before the captain could reply, a voice broke in and replied, "Oh, bombs, rockets -- atom bombs."