Its bearded 50-year-old leader has assumed hero status in the impoverished Palestinian territory, where he says his group plans to spend $25 million on housing, medical care and education.
Mehmet Kaya has been treated like a star wherever he goes since the deadly raid on Monday. Gazans young and old gather to shake his hand, and he enjoys ready access to leaders of the territory's ruling Islamic militant group Hamas.
"The Arab countries that are a part of us haven't done what Turkey did," said Jihan Balousha, 30, who bought her five children to meet Kaya at Gaza's dilapidated port Wednesday.
It's all part of Turkey's muscular push into the blockaded Gaza Strip and its growing ambition to be an influential player in the Middle East.
Israel accuses Kaya's group, known by its Turkish acronym IHH, of supporting terrorism. The Turkish activists vehemently deny that, saying they're strictly involved in humanitarian efforts and have to deal with Hamas, since it is the authority in Gaza.
"We have found that the support, when it goes through the Hamas government ... it goes to the people," said Kaya, the Gaza representative for the group, whose name in English means Foundation for Human Rights and Freedoms and Humanitarian Relief.
Kaya has gained new prominence since the six-ship flotilla tried to challenge Israel's 3-year-old blockade of Gaza. The attempt ended with Israeli commandos commandeering the boats and clashing with club-wielding passengers on one vessel in a confrontation that left eight Turks and an American dead.
Seen as a kind of unofficial ambassador to Gaza, Kaya symbolizes Turkey's dramatic shift toward Hamas' key patrons Iran and Syria, at the expense of its traditional alliance with Israel.
Ties had been warming gradually, but the sea raid pushed the fledgling partnership out into the open as Turkish Prime Minister Recep Tayyip Erdogan railed against Israel, accusing it of committing a "massacre" on the high seas.
Israeli-Turkish ties had been showing signs of strains even before the raid. Erdogan was an outspoken critic of Israel's war in Gaza last year and in one high-profile incident, stormed off a stage he was sharing with Israeli President Shimon Peres at Davos in the days after the war.
Turkey's government unofficially sponsored the flotilla, which was transporting 10,000 tons of aid and hundreds of activists. In the weeks before the operation, Israeli military and diplomatic officials repeatedly urged Turkey to call off the flotilla, a request that was rebuffed in Ankara.
IHH insists it has no ties to Turkey's Islamic-leaning government, though its top fund-raisers are believed to be among Erdogan's core support group, the country's wealthy merchant class.
Signs of the warm Turkish-Gaza ties are popping up around the territory.
'This fits well with their past'
A Hamas statement quoting Erdogan as telling the Islamic militant group's leader, Ismail Haniyeh, by phone that "we will continue to support you even if we remain alone" was widely distributed and posted on mosque walls in Gaza this week.
The IHH is renovating the port, funding a Turkish-Palestinian school and plans to build a hospital and apartments for Gazans made homeless during the war with Israel early last year. The group also supports 9,000 families with money and food parcels, and is hosting computer and sewing courses for women, Kaya said.
Israel imposed the blockade after Hamas, which most Western countries consider a terrorist organization, seized power in Gaza and stepped up rocket fire into Israel.
The United Nations, which was to lead reconstruction efforts after the Gaza war ended early last year, has been paralyzed because Israel does not allow in building materials. UN aid agencies are not permitted to buy goods brought in through Gaza's smuggling tunnels.
Groups like IHH have filled the void because they can use black market goods and - unlike the international agencies - are under no obligation to stay away from Hamas.
In the war-ravaged Gaza neighborhood of Izbet Abed Rabbo, IHH is building a three-story apartment block for families made homeless during the Gaza war. The $250,000 project provides jobs for 100 people.
As the IHH shot to attention, so have Israeli accusations that it supports terrorism. Israel has been trying to defuse widespread international anger over the sea raid, arguing that its troops came under premeditated attack and fired in self defense.
"The IHH is ... known as a group implicated in terrorist operations," said Israeli Foreign Ministry spokesman Yigal Palmor. "Their close ties with Hamas are an avowed policy of this group."
The IHH's website shows its founder warmly embracing Hamas' exiled leader, Khaled Mashaal, in Syria. Hamas has killed hundreds of Israelis in suicide bombings and other attacks.
On Wednesday, former French anti-terrorism judge Jean-Louis Bruguiere, who investigated the group in the 1990s, said he found links to terrorism networks, including al-Qaida, but didn't say whether IHH now has terror ties.
Israel's Shin Bet security service says the group is a major player in raising funds for Hamas.
Reuven Erlich, head of the Intelligence and Terrorism Information Center, an Israeli think tank with close ties to Israel's Defense Ministry, said the group "in the past provided at least logistical support to Islamic jihad organizations," including funds and arms.
"We were not surprised when we heard what happened," Erlich said. "This fits well with their past."
Despite such claims, the IHH, unlike Hamas, is not among some 45 groups listed by the U.S. State Department as terror organizations.
IHH board member Omer Faruk Korkmaz said his group is strictly involved in delivering aid.
"We don't approve of the actions of any terrorist organization in the world," he said in an interview at the group's Istanbul headquarters Wednesday.
Gaza residents say they appreciate the IHH and Turkey for spotlighting Israel's harsh blockade on the territory.
"They have really stood beside us, and we are grateful," Balousha said.