Today they're expecting a fight, as they head south. It's a hard slog through sweltering cornfields in burning heat.
Their mission right now is to help some of Helmand's 615,000 registered voters get to the polls, in spite of Taliban threats.
"From what we heard the Taliban said that if any civilians vote they will chop off their fingers," Lance Corporal Anthony Correlli said.
The Taliban are not accustomed to having the Marines in their backyard.
This time, Echo Company wants them to know they're coming.
The choppers fire flares as the Marines push further south than they've ever been.
Suddenly shots ring out and the Marines get down. Then the order comes to run for cover behind a nearby berm.
It's exactly what the Marines expected. As we moved through the open ground we took small arms fire. These guys are not put off by the show of power, the air support. They are dug into fighting positions in buildings while the Marines are out exposed, using every piece of ground they can find for cover.
The anticipated fight doesn't come and the Marines head home.
"Each time we go down there we've made a fight so today was a little strange," said Captain Eric Meador, commander of Echo Company. "It could be linked with tomorrow's elections; it could be that they have people that normally fight us here that might be off in other areas doing other things."
Echo Company will be out on election day, reassuring local people that it's safe to vote.
But even they don't believe it will make much difference here, where the Taliban holds more sway than anyone else.
CBS News' Lara Logan's coverage of Afghanistan:
Marines Walk Tightrope of Death
Mission Critical for U.S. Troops in Afghanistan
What the Afghans Really Want
Reporter's Notebook: With the Marines in Helmand Province