As you mentioned, it carried a lot of people, but no aid. All of the aid was on four of the other ships. Thus, the Mavi Marmara was not a humanitarian aid ship. It was a ship containing a group of people who wished to make a political statement about the blockade.
Reports of what took place on that ship are contradictory. However, the reaction from the passengers to the IDF was definitely very different from the reaction of the passengers on the other ships.
Here is an article from the NY Times that I would encourage you to take a look at.
It includes direct statements from individuals who were on board that ship.
Excerpt:
The crack of an Israeli sound grenade and a hail of rubber bullets from above were supposed to disperse activists, but instead set them in motion. And when three Israeli commandos slid down ropes out of helicopters to take over the ship, a crowd set upon them.
“They ran at them without pause or hesitation,” Dr. Coskun recalled.
One soldier was stabbed and two were beaten. From that moment on, the attempted takeover turned into an armed assault, with angry Israeli commandos opening fire. Within an hour, the commandos had taken control of the ship, and nine Turks, including one who also had American citizenship, were dead.
Dozens of interviews in Israel and Turkey suggest that Israel’s decision to stop the flotilla at all costs collided with the intention of a small group of Islamic activists from Turkey, turning a raid on a ship of protesters in international waters into a bloodbath — and a major international event.
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It was a small group of aggressive activists on the upper deck who overwhelmed the first soldiers, wrenching away their weapons and, according to Dr. Coskun and video images supplied by the Israeli military, beating them with wooden poles and metal rods that they had ripped or sawed off the side of the boat.
http://www.nytimes.com/2010/06/05/world/europe/05reconstruct.htmlPassive, non-violent resistance was not the approach used by some of the passengers on this particular ship.
It was on the others, where no one was killed.