When Marines of Alpha and Bravo Companies, 1st Battalion, 6th Marines, pushed into Garmsir, a Taliban stronghold, before dawn Tuesday, each toted 18 half-liter bottles of water plus two liters in his pack. Their staggering 100- to 150-pound loads - including weapons, ammunition, mortar base plates, radios, flak vests and helmets and other gear - had troop commanders worried even before the operation began.
Carrying all this, the Marines have struggled night and day across fields of dust and weeds, kneeling or flopping prone to get "eyes on" the enemy or to take cover from fire, then laboriously pushing themselves to their feet to cross irrigation ditches and patrol along green fields of wheat and pink and white poppies.
And in the 100-degree heat, the water has gone down fast.
Only hours into the mission, some platoons were reporting they were low on water. By nightfall, the Marines had asked for an unscheduled resupply of water.
The pallets of bottled water came by CH-46 helicopter from FOB (Forward Operating Base) Dwyer, a major supply base in southern Afghanistan.
Dwyer itself had just received its own resupply of water. Because of the time and risk of ground convoys, the pallets of bottled water came tumbling out of the sky under parachutes.
Alpha and Bravo reported several heat casualties, handled by their own Navy corpsmen. One corpsman, Petty Officer 2nd Class Timothy Altizer, 27, from Princeton, W.Va., was treating Marines with shade, cool water and in some cases intravenous fluids - and rest.
Some of the Marines' missions were delayed until night, allowing them to find shade in the cool mud-and-adobe compounds, lent by local farmers. There, the Marines would shuck their rucksacks and sprawl asleep in helmets and flak vests, in some cases under the curious gaze of chickens and goats.
The high consumption of water was a complication for the Marine battalion, which had to balance the resupply of ammunition and water with available helicopter airlift. By midweek, that adjustment had been made and daily water resupply was under way, said Maj. Tom Clinton, battalion executive officer.
"This is just reality buffering up against the plan," he said.
Alpha Company's commander, Capt. Sean Dynan, spent hours last week fretting over the loads his men would carry and their mission of assaulting a Taliban stronghold by helicopter and spending days seeking out and fighting Taliban insurgents.
"I don't want to be in a situation where we go red [empty] on ammunition because we didn't bring enough," he said one night. "But I don't want my guys going down with dehydration because we brought too much."
Hours before the mission began, Dynan and company 1st Sgt. Scott Hamm went through each Marine's pack, tossing aside extra underwear, toothpaste and candy bars to shave down the weight.
Dehydration and the heavy loads cascaded into other problems as Marines struggled to keep their footing along the narrow ditches and 20-inch-high baked earth irrigation dikes hidden beneath hip-high grass, wheat or poppies.
Lance Cpl. Zach Bell suffered an injury common this week, slipping and badly twisting an ankle as he negotiated his load, including 20 pounds of ammunition, along the slick edge of an irrigation ditch. He was sent by helicopter to the surgical facility at FOB Dwyer.
"I knew it was going to be tricky, so I tried to be real careful with my steps," he said with regret.