In regards to maritime laws, I believe the ships in question must fly the flag in which country it is registered and must comply to all the laws of the sea, up to and including a legal blockade. The crews of the ships in question would be ultimately be responsible for it's crew and passengers. To sail deliberately into a hostile situation and as a result deaths occur aboard this ships , would be the responsibility of the Captain and owners of these vessels. Smuggling is also taken very seriously and I believe can be considered as a hostile or even a wartime ship. Then again I could be completely wrong on this but, if I was Israel I would have all the Maritime lawyers working on this and if in fact this was the case I would bring suit to the countries and owners and captains of these vessels.