Under international maritime law you are legally entitled to resist unlawful capture, abduction and detention http://usa.mediamonitors.net/content/view/full/75086

"...according to international law, the actions of the Israeli military were beyond the law and those involved should be treated no differently than, say, the Somali pirates who are also in the habit of boarding ships by force....Any rights to self defense in such dramatic circumstances rests purely with the passengers and crew on board. Under international maritime law you are legally entitled to resist unlawful capture, abduction and detention."