Sgt. James Amadio waits before getting on board one of the MKII combat support boats that are used to patrol the Tigris River in north Baghdad. (Kent Harris / S&S)

Sgt. James Amadio waits before getting on board one of the MKII combat support boats that are used to patrol the Tigris River in north Baghdad. (Kent Harris / S&S)

A young boy swims in the Tigris River. Local Iraqis have apparently managed to build up an immunity to bacteria in the water, but U.S.soldiers know better than to take a plunge or get a drink. (Kent Harris / S&S)

Iraqi policeman on one MKII combat support boat look out over the Tigris River on Friday, while the lead boat travels ahead. Policemen have joined American soldiers in patrolling the historic river. (Kent Harris / S&S)

Soldiers riding aboard an MKII combat support boat on the Tigris River have to be prepared to defend themselves. The patrols are usually uneventful, but occasionally someone wants to take a shot at one of the boats. (Kent Harris / S&S)

An Iraqi teen jumps off a bridge on his way into the Tigris River. Young Iraqis seem fearless around the river, whether it’s jumping from a high spot into it or splashing around a pipe that’s pouring smelly material into the water. (Kent Harris / S&S)

BAGHDAD, Iraq — For soldiers who paid attention during high school history classes, a trip on the Tigris River has more significance than a typical patrol through the capital city.

“This is like you read it in the text books,” Pfc. Justin Brown, says as he scans the banks of the river for possible trouble. “It’s just awesome.”

Brown and other members of the 1st Battalion, 13th Armored Regiment — part of the 1st Armored Division’s 3rd Brigade from Fort Riley, Kan. — have been tasked recently with providing security firepower for the reservists who own and operate the boats used to patrol the river.

“Our section got volunteered for this mission,” said the native of Chico, Calif. “I didn’t know how much fun it was going to be.”

“Fun” is not a word generally used to describe a patrol in Baghdad. And there are certainly elements of the river patrols that aren’t fun.

The reservists, who hail mostly from Oregon and Washington, have been conducting the patrols since April. They’ve come under fire several times. And they know they’re more vulnerable while they’re riding the waters.

But it’s a change of pace for most soldiers. Brown’s battalion usually rides around in tanks, although his job is working in supplies.

But now he’s floating on a river that has seen the rise and fall of a dozen civilizations.

People have been navigating the Tigris long before there was an Iraq. Along with the Euphrates River, the Tigris forms what many believe is the cradle of civilization.

Ancient Babylonia is now mostly ruins. But the Tigris continues to flow — not that it hasn’t changed over the years.

One of the biggest changes came after Turkey built a dam upstream, severely cutting the amount of water that flows into Iraq. The water that’s left isn’t exactly pristine — at least in the case of the part that runs through Baghdad.

Spc. Eric Ramos said he and fellow soldiers have ventured upstream beyond the city a few times. He said the water there is “crystal clear.”

But pipes empty material that smells like sewage into the river as it runs through Baghdad. Ramos says the water gets worse farther downstream after it passes by an oil refinery.

That doesn’t stop dozens and dozens of children — and a handful of adults — from taking a swim. Many of the kids hang out in the river all day.

Some of the brave — and perhaps foolhardy — climb onto one of the bridges that span the river and jump into the murky water below.

But soldiers aren’t as interested in what’s in the water these days as what’s on it.

That’s supposed to be fishermen. But months ago, some Iraqis seemed to be fishing with guns. Or, at least, that was the argument.

“They have no reasons to carry weapons on a fishing boat,” says Sgt. Jim Oakes, who is in charge of the two-boat patrol.

The patrols are conducted on MKII combat support boats. They’re used mainly in helping soldiers build pontoon bridges. The reservists have built a few of those. But the main mission now is using the boats to patrol the river.

PT boats they’re not. The only firepower comes from the soldiers stationed on board. The bridges that span the river present dangers of someone dropping something or firing from above. So soldiers are most alert when passing underneath, training their weapons up along the bridge.

Oakes hasn’t seen many illegal weapons lately. Early patrols got the message across that the U.S. military wouldn’t let any attacks or gun-smuggling happen on the Tigris.

So lately, they’ve been looking for suspicious activity on the shoreline. When soldiers see or hear something, they notify someone on the ground nearby.

They’ve also started taking Iraqi policemen along. The goal, as it is in most patrols around the country, is that the locals will eventually take over the missions, leaving soldiers free for other duties — or free to leave the country.

At least a few of them will have some stories to share when they do that.

“When I get back, I can say I’ve been on [the Tigris],” says Spc. Brian McQueen.