Concern about more violence loomed large as Israel stood fast by its blockade, despite rising pressure to lift it following Monday's raid against another aid ship that left nine activists dead.
Irish Nobel Peace Prize laureate Mairead Corrigan, who was on the ship with other activists, said they were determined to press on but would offer no resistance if Israeli forces came aboard.
"We will sit down," she said. "They will probably arrest us ... But there will be no resistance."
A spokeswoman for the Free Gaza Movement, Greta Berlin, said Friday evening that the ship, the 1,200-ton Rachel Corrie, was 110 miles from Gaza and was expected to reach the seaside strip by Saturday morning.
Israeli Prime Minister Benjamin Netanyahu told his Cabinet on Thursday night that the boat would not reach the territory. On Friday, Israel's foreign ministry said the policy had not changed.
"There is a maritime blockade on Gaza," ministry director Yossi Gal said.
The new effort to break the blockade will test Israel's resolve as it faces a wave of international outrage following Monday's botched raid, in which Israeli commandos clashed with activists after rappelling onto a ship from helicopters. Eight Turks and an American of Turkish descent were killed and hundreds of others on the ship were arrested and later deported.
The fallout has increased pressure to end the embargo that has plunged Gaza's 1.5 million residents deeper into poverty and sharply raised Mideast tensions at a time the U.S. is making a new push for regional peace.
Israel has urged the activists to bring the ship to the southern Israeli port of Ashdod and promised to transfer all cargo save any weapons or weapons components. The activists rejected the Israeli offer.
Netanyahu has instructed the Israeli military to avoid harming the passengers on board the Rachel Corrie, a participant at Thursday night's Cabinet meeting said. He spoke on condition of anonymity because the meeting was closed.
Gal said Israel has "no desire to board the ship. If the ship decides to sail to the (southern Israeli) port of Ashdod, then we will ensure its safe arrival and will not board it."
In Washington, the State Department said U.S. officials had been in touch with "multiple" countries, including the Israeli and Irish governments, about the latest effort.
"Everyone wants to avoid a repetition of this tragic incident," spokesman P.J. Crowley said. He added that the U.S. had been in contact numerous times with Israeli authorities in recent weeks. "We urged caution and restraint," he said.
International condemnation continued Friday, with protests in Syria, Greece, Bahrain and Malaysia, where some demonstrators burned Israeli flags and carried mock coffins. In Norway, the military canceled a seminar scheduled for later this month because an Israeli army officer was to have lectured.
Israel has allowed ships through five times, but has blocked them from entering Gaza waters since a three-week military offensive against Gaza's Hamas rulers in January 2009.
Israeli claims the activists ambushed the commandos after they descended onto the board from helicopters on Monday, and the military and Turkish TV have released videotape that backs up that claim. Returning activists admitted fighting with the Israeli commandos but insisted their actions were in self-defense because the ships were being boarded in international waters by a military force.
All of the violence took place on the lead boat, the Mavi Marmara, which was carrying hundreds of activists sponsored by an Islamic aid group from Turkey, the Foundation for Human Rights and Freedom and Humanitarian Relief. Israel outlawed the group, known by its Turkish acronym IHH, in 2008 because of alleged ties to Hamas.
Activists say Israel sabotaged the previous aid flotilla, but Israeli defense officials said Friday only that unspecified "actions" were taken when the boats were still far from Gaza that delayed the flotilla. They spoke on condition of anonymity because the information was classified.
Activists said immediately after the raid that the violence would not deter them from sending more ships, and the Rachel Corrie continued on course for Gaza, carrying hundreds of tons of aid, including wheelchairs, medical supplies and concrete. Eleven passengers were on board, including Corrigan and a former U.N. humanitarian coordinator in Iraq, Denis Halliday.
"We will not be diverted anywhere else. We head to Gaza in order to deliver the humanitarian aid and to break the siege of Gaza," Corrigan said. "As human rights activists we want to see Israel uphold human rights and international law and end the military occupation of Palestine and move forward."
Halliday told Israel's Channel 2 TV the cargo had been inspected three different times in Ireland by trade unions and government officials, "so we are 100 percent confident that there is nothing that is offensive or dangerous or otherwise." He acknowledged that Israel might object to the 500 tons of cement on board; Israel claims militants can use the cement for battle purposes.
The vessel is named for an American college student who was crushed to death in 2003 by a bulldozer while protesting Israeli house demolitions in Gaza.
Berlin, the spokeswoman for the Free Gaza Movement, said in Nicosia that the cargo ship was headed directly to Gaza and would not stop in any port on the way.
The standoff has particularly strained Israel's relationship with once-close ally Turkey.
Turkish Prime Minister Recep Tayyip Erdogan kept up the tough rhetoric on Friday, telling a crowd that "nobody should test Turkey's patience."
"Even if the world turns a blind eye to the massacre, Turkey will never do so," he said in a speech in the central Turkish city of Konya that was punctuated with calls of "down with Israel" from the crowd.
Deputy Prime Minister Bulent Arinc also announced Turkey was downsizing its economic and defense cooperation with Israel.
About 20,000 people, meanwhile, waved Turkish, Palestinian and Hezbollah flags at a memorial service in Istanbul for an IHH member who activists say was killed while taking pictures of the Israeli commando raid.
Anger also was high as 10,000 people turned out to bury the youngest of the nine activists killed, 19-year-old Furkan Dogan in the central Turkish town of Kayseri.
"Neither I nor his mother or brother have any grief," his father, Ahmet Dogan, told the AP as he arranged flowers on his son's coffin before prayers started. "We believe he became a martyr and God accepts martyrs to paradise."