Echo Company is heading out to a known Taliban village just a mile from their small combat outpost deep in southern Helmand.
This time they've chosen an unusual way in. By coming through a canal, the Marines are hoping to have the element of surprise.
In the month and a half since Echo company fought their way in, they've never been to this village without getting into a fight. And they've never been all the way in water that's often up to their necks.
Sergeant Anibal Paz advises his troops that they've been spotted and says over the radio that there are four military aged males due west. He says the mission will continue, however.
The Marines keep going even though they now realize they could be heading straight into an ambush.
Read more about the upcoming election from CBS News correspondent David Martin.
Read more from Lara Logan about the Marines in Afghanistan and her thoughts about the election in CBSNews.com's World Watch blog here.
They're trying to secure the area so people can vote. But the nearest polling station is 12 miles to the north and along the way is hardcore Taliban territory. So few people are expected to make the journey.
The troop pauses again. This time it's to search for IEDs, or improvised explosive devices - a Taliban weapon of choice. Marine engineers go ahead to clear the route. They quickly return, hurrying to get away from an IED they've just found in the exact place they often use to enter the village.
The Marines have just found an IED in their way so everyone's pulling back so they don't get blown up
After four hours in the water waiting to destroy the IED, the marines get word the enemy has moved out. They start to head back, taking cover as the IED is finally blown up.
It's rare for these Marines not to get into a gun battle. They say it will happen tomorrow, like it has almost every day since they arrived.