ABOARD THE USS SHILOH -- It was the kind of day pilots dream of -- clear skies with visibility all the way to the horizon.

Up in a U.S. Navy Seahawk helicopter, Lt. Sean Foss and Lt. j.g. Nate Rodenbargar were on patrol, providing an extra set of eyes for the USS Shiloh.

Approaching a lone tug boat Sunday afternoon, they swooped in low to get a better look -- even such innocuous-looking vessels might be hiding sea mines.

As soldiers from the U.S.-led coalition move deeper into Iraq, the chance of an attack on warships in the Persian Gulf grows slimmer. But threats remain, and helicopters from the U.S. Navy are on the lookout.

In ordinary times, tugs cruising the Gulf are not unusual. But Australian forces intercepted an Iraqi barge carrying 68 mines on Friday. It was being pulled by two tugs, and the Australians said the Iraqis planned to release the explosives into the Gulf

"After they caught that tug with mines, they all look like minelayers to me," Petty Officer 1st Class Spencer Stallman told Foss and Rodenbargar by radio aboard the Shiloh.

Seahawks take flight

Dozens of Seahawks based on U.S. Navy cruisers are flying low in the skies over the Gulf, performing what the Navy calls Armed Surveillance and Reconnaissance missions. The Seahawks -- a maritime version of the better-known Army Black Hawks -- were designed for just such a mission when they were first commissioned in the 1980s.

U.S. Navy cruisers depend on radars to detect hostile ships before threats are in range to fire.

But radars can only see as far as the horizon, between 10 and 20 miles for cruisers, and Seahawks increase that range.

The helicopter's radar, which can see for over 100 miles if conditions permit, is linked directly to the ship through a special system called the "hawk link."

Cruisers carry two of the helicopters and the Navy has begun putting them on destroyers as well.

Stallman took a look at the tug through a feed from the Seahawk's Forward Looking Infrared camera, or FLIR. But the grainy, green-tinted black and white image didn't tell him much.

"See if you can get a good look at his details -- name, port of registration," he radioed to the pilots from the ship's combat information center, the darkened room deep in the cruiser where sailors monitor radars and tracking devices.

Dozens of coalition warships -- carriers launching fighters jets, cruisers firing Tomahawk missiles -- are concentrated in the Persian Gulf.

To Foss and Rodenbargar, the tug didn't raise any red flags. The boats seemed to be traveling at a normal speed and appeared to have the usual number of crew.

After a few passes, Foss, a 27-year-old from Fairfax, Va., and Rodenbargar, 26-year-old from Annapolis, Md., headed off to get a look at a nearby tanker.

Aside from their reconnaissance mission, Seahawks are equipped with search and rescue equipment, sonar buoys used to hunt submarines and a .50 caliber gun and hellfire missiles to take on small to mid-sized ships.

The search and rescue tools almost came in handy Friday, when two British helicopters crashed over the Gulf. At least one Seahawk was dispatched to help out, but a U.S. destroyer got to the scene first.

As for the weapons, which have only been added in the last five years, pilots haven't gotten a chance to use them yet.

"I thought when we got back here, we'd definitely get a chance to take out some of those PB-90s (Iraqi patrol boats)," said Lt. j.g. Gabe Kelly, a 26-year-old from Coronado, Ca.

The Shiloh, based in San Diego, spent the fall in the Gulf and the pilots flew numerous missions shadowing Iraqi boats.

"We come back here and we think, sweet, we're finally going to get to take them out," he said.

They didn't. Instead, an Air Force AC-130 gunship got the assignment.