I was sent this today by someone arguing for Israel's side.
It's the international law applicable to armed conflicts at sea.http://www.icrc.org/ihl.nsf/385ec082b50 ... 1f002d49ce
Here are the relevant paragraphs concerning civilian vessels being attacked:
SECTION V : NEUTRAL MERCHANT VESSELS AND CIVIL AIRCRAFT
Neutral merchant vessels
67. Merchant vessels flying the flag of neutral States may not be attacked unless they:
(a) are believed on reasonable grounds to be carrying contraband or breaching a blockade, and after prior warning they intentionally and clearly refuse to stop, or intentionally and clearly resist visit, search or capture;
(b) engage in belligerent acts on behalf of the enemy;
(c) act as auxiliaries to the enemy s armed forces;
(d) are incorporated into or assist the enemy s intelligence system;
(e) sail under convoy of enemy warships or military aircraft; or
(f) otherwise make an effective contribution to the enemy s military action, e.g., by carrying military materials, and it is not feasible for the attacking forces to first place passengers and crew in a place of safety. Unless circumstances do not permit, they are to be given a warning, so that they can re-route, off-load, or take other precautions.
68. Any attack on these vessels is subject to the basic rules in paragraphs 38-46.
69. The mere fact that a neutral merchant vessel is armed provides no grounds for attacking it.
Okay, here is 38 - 46:
PART III : BASIC RULES AND TARGET DISCRIMINATION
SECTION I : BASIC RULES
38. In any armed conflict the right of the parties to the conflict to choose methods or means of warfare is not unlimited.
39. Parties to the conflict shall at all times distinguish between civilians or other protected persons and combatants and between civilian or exempt objects and military objectives.
40. In so far as objects are concerned, military objectives are limited to those objects which by their nature, location, purpose or use make an effective contribution to military action and whose total or partial destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage.
41. Attacks shall be limited strictly to military objectives. Merchant vessels and civil aircraft are civilian objects unless they are military objectives in accordance with the principles and rules set forth in this document.
42. In addition to any specific prohibitions binding upon the parties to a conflict, it is forbidden to employ methods or means of warfare which:
(a) are of a nature to cause superfluous injury or unnecessary suffering; or
(b) are indiscriminate, in that:
(i) they are not, or cannot be, directed against a specific military objective; or
(ii) their effects cannot be limited as required by international law as reflected in this document.
43. It is prohibited to order that there shall be no survivors, to threaten an adversary therewith or to conduct hostilities on this basis.
44. Methods and means of warfare should be employed with due regard for the natural environment taking into account the relevant rules of international law. Damage to or destruction of the natural environment not justified by military necessity and carried out wantonly is prohibited.
45. Surface ships, submarines and aircraft are bound by the same principles and rules.
It doesn't seem to mention international waters nor domestic waters, but it does mention having justification attacking if that ship is intent in breaching a blockade.
So here's the sticking point: Israel's blockade - LEGAL?
The law as the public knows it seems to be written by the media - the MSM, regardless of what the UN says.