NOT in International waters though. You know things like international laws etc.
International waters don't give you immunity, they had a stated aim, though a debatable one when it comes to international law, but assuming they were given a reasonable opportunity to change course, and there were reasonable and safe options for changing course, it isn't piracy - similar situation with the Russian tankers. I don't agree with Israel here but protest action aside it isn't like it was going to go any differently with potential to go much worse.