A Spanish ship towing a barge loaded with 200 tonnes of desperately needed food supplies for Palestinians in Gaza has finally set sail from Cyprus.
The Open Arms left Larnaca just before 09:00 (07:00 GMT) on a journey which could take as long as two days.
Gaza has no functioning port, so the US charity behind the mission, World Central Kitchen, is building a jetty to receive the aid.
The UN warns that massive aid shortages have left Gaza on the brink of famine.
The quickest, most effective way to get aid into the territory is by road. But aid agencies say Israeli restrictions mean a fraction of what is needed is getting in.
If the Open Arms successfully docks in Gaza, then other ships will follow as part of a European and Emirati maritime effort to get more aid into Gaza.
Israel says it welcomes the creation of a maritime corridor and that it is facilitating the transfer of aid to Gaza while its forces continue to fight Hamas.
The war began when Hamas gunmen attacked southern Israel on 7 October, killing about 1,200 people and seizing 253 hostages. More than 31,180 people have been killed in Gaza since then, the Hamas-run health ministry says.
World Central Kitchen (WCK) announced that its first maritime shipment of aid was on its way to Gaza on Tuesday morning after weeks of preparation.
The Open Arms - a salvage vessel belonging to a Spanish charity of the same name - is towing a barge filled with rice, flour, legumes, canned vegetables and canned proteins.
While it is at sea, Palestinians working for WCK will continue building a jetty at an undisclosed location on Gaza's coast, which will be used to offload the aid. They are using rubble from buildings and infrastructure destroyed over the last five months.
If the jetty is ready in time, WCK says it will load the food on to lorries and distribute it to communities in need. The charity has a network of some 60 kitchens across Gaza and has provided more than 35 million meals to the estimated 1.7 million displaced Palestinians there.
"'Operation Safeena', (boat, vessel) on its way! First trip to the shores of Gaza, learning," WCK's founder, Spanish celebrity chef José Andrés, wrote on X, formerly Twitter. "At the same time as [Open Arms] is moving, construction of the jetty is well under way."
"We may fail, but the biggest failure will be not trying! Thank you to all that made it possible... We could bring millions of meals a day... The people of the north will be fed!" he added.
The UN says at least 576,000 people in Gaza - one quarter of the population - are one step away from famine.
It warns that time is running out for the estimated 300,000 people isolated in the north of the territory, which UN agencies have struggled to access for several months due to the ongoing hostilities and a breakdown of law and order.
Gaza's health ministry says at least 25 people, many of them children, have died as a result of malnutrition and dehydration at hospitals there.
On Tuesday, Palestinian media reported that nine people were killed by Israeli fire as they waited for aid lorries to arrive at Kuwait Square in Gaza City, which is in the north. There was no immediate comment from the Israeli military.
"We are being starved in two ways: food is scarce, and the little that is available is so expensive as to be beyond imagination," Yamen, a father of four whose family is sheltering in the central town of Deir al-Balah, told Reuters news agency on Tuesday.
WCK says it is has another 500 tonnes of aid in Cyprus ready to be shipped and that its goal is to establish a "establish a maritime highway of boats and barges stocked with millions of meals continuously headed towards Gaza".
The Open Arms is the first aid ship to set sail as part of a maritime corridor initiative by Cyprus, with the support of the European Union, the UK and US.
Cypriot President Nikos Christodoulides said its journey was "one of hope and humanity" and that it might become a "lifeline to civilians".
The US has also launched a separate initiative which will see a military ship build a floating harbour off Gaza's coast, including a temporary pier to transport supplies to the shore.
Western and Arab countries have also been carrying out airdrops, mostly over northern Gaza. However, they are considered ineffective and costly.
The UN says road routes are the only option to transport the large quantities of food needed to avert famine.
It is urging Israel to open crossings with the north, which were closed after the 7 October attacks, and allow the use of the nearby port of Ashdod.
Israel denies impeding the entry of aid or its distribution, and blames UN agencies for failing to get the aid that is allowed in to the people who need it.
About 500 lorries - suitable for carrying up to 20 tonnes of material - crossed into Gaza each day on average before the war. In the first 10 days of March, an average of 162 lorries entered Gaza daily via the Egyptian-controlled Rafah and the Israeli-controlled Kerem Shalom crossings, according to the UN.
