Their supplies will feed 200,000 Haitians for a month, so the army and navy are delivering a precious cargo.
Islanders recovering from their devastating earthquake have been boosted by packages delivered by the army from the fleet auxiliary ship Largs Bay.
Since its arrival last month the amphibious vessel has been a vital link in the chain providing support to villagers left with nothing.
And now soldiers from 17 Port and Maritime Regiment of the Royal Logistics Corps have gone out to remote areas to make sure food supplies reach their targets.
They are currently working in the Gonaives, 70 miles from the capital Port Au Prince.
The Department for International Development is leading the mercy mission but troops are also working with international groups such as the World Food Programme (WFP).
Mary O'Neil, the port captain for the WFP and principal organiser of the aid delivery, said: 'Our arrival in Gonaives displays the versatility of the excellent ship Largs Bay and the niche capability that it has brought to Haiti.
'This is the first time that the WFP has worked so closely with a maritime military organisation and Largs Bay is just perfect for our needs.'
Largs Bay's delivery has saved hundreds of lorry drivers from having to risk their lives driving supplies on remote roads damaged by the disaster.
Mrs O'Neil said: 'We are in a race against time to transport as much essential and high value cargo as possible before the rains arrive.
'This cargo alone has prevented an extra 300 lorry loads travelling the precarious coastal road and saved me two weeks work.
'At the same time those lorries can be put to better use clearing out the local environs of Port au Prince which still has so much work to be done,' she added.
The unloading of the cargo is a three-day operation that is happening during reconstruction work.
Lieutenant Commander Dickie Walters, who is with Largs Bay, said: 'As part of the DfiD initiative, the projects will be refurbished using a cash for work scheme.
'Local tradesmen and contractors will complete the work ensuring that money is generated where it is needed most.'
RICE AND PEAS THE FOOD ESSENTIALS
RFA Largs Bay has been loaded down with sacks of food to keep Haitians from hunger after the devastating quake.
Its cargo includes 3,600 sacks of peas, 4,050 sacks of rice and 7,392 cartons of ready to eat meals.
With that amount there will be enough supply to feed 200,000 Haitians for a month.
The food is being shared out in the remote area of Gonaives, about 70 miles from Port au Prince.
Meanwhile the islanders are trying to cope with a string of infrastructure problems - not least the disappearance of 5,000 criminals.
When the quake struck guards fled the island's prisons leaving people in their cells, and afterwards many were able to break out and take refuge in the chaos.
In the main squares of the larger towns makeshift tented accommodation has been set up, which one Largs Bay sailor described as looking like the Glastonbury festival without the entertainment.
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