The 22nd Marine Expeditionary Unit are headed for the Caribbean aboard the amphibious ships USS Bataan, Fort McHenry and Carter Hall.
About 2,000 Marines are bringing trucks, earth-moving equipment and water purification systems to support the disaster relief effort.
Their mission has not been fully defined yet. Water purification will be a focus, as will clearing rubble and engineering, but they could also find themselves helping keep the peace if that devastated country slips into lawlessness.
The 22nd Marine Expeditionary Unit just back last month from a seven month deployment to Europe and the Middle East, but this time they are providing humanitarian relief.
"It's not going to be anything like they've seen before," 22nd MEU Chaplain Jim Dewey said.
The 22nd Marine Expeditionary Unit will arrive in Haiti early next week along with Marines on a fourth ship that'll be joining them en route.
Meanwhile on Friday, over 100 paratroopers from the Bravo Troop, 1st Squadron, 73rd Cavalry Regiment at Fort Bragg was finally able to lend aid after being delayed Thursday, because Haiti's airport was overloaded as relief flights from all over the world tried to land.
ABC11's Larry Stogner is embedded with the unit and is reporting from Haiti.
He said soldiers unloaded choppers full of water brought in from the aircraft carrier Carl Vinson on Friday.
"They're just getting acclimated and used to the pace and the confusion," Stogner said. "Later they will move outside of the gates into a world they can only imagine."
Getting the supplies and the soldiers to Haiti has been hampered by few available aircraft and chaos at the airport.
By the end of Friday officials said there were to be about 1,000 U.S. troops in Haiti.
Army and Air Force planners say they are determined to find a way to get thousands of Fort Bragg boots on the ground in Haiti as fast as possible.
A full brigade from the 82nd Airborne will be in Haiti by Sunday. A brigade normally is about 3,500 soldiers.
Commanders say Fort Bragg troops could be in Haiti 60 to 90 days.
"What we are doing here is planning and execution pushing our troops down to Haiti," 82nd Airborne Maj. Brian Fickle Spokesperson said. "We are also palling for what is after today, what we are doing next week & how we are going to re-supply the guys we just sent down today."
As thousands of members of the 18th Airborne Corp., the 82nd Airborne deploy to Haiti, another 2,500 will remain at Fort Bragg on standby in case they are needed.
"In this mission we are going to be there in a humanitarian role," 82nd soldier Sgt. Matthew Jordan said. "And its refreshing to go with that purpose of helping the country helping the people."
The paratrooper brigade has been one of the division's most frequently deployed units - its soldiers have been sent to Iraq or Afghanistan seven times. The 82nd's 2nd Brigade Combat Team is the U.S. military's global response force. The unit has been on 24/7 standby since June, ready to deploy anywhere in the world within 18 hours.
"It's not a combat mission it's not an operation from that standpoint, they'll be wearing soft caps they'll be in a very submissive environment to where they're going in and really providing that level of support," Fort Bragg Spokesman Col Billy Buckner said.
President Obama has promised an all-out rescue and humanitarian effort including military and civilian emergency teams from across the U.S.