Once again, the emphasis is on protecting "civilian" as opposed to "military" or "military objective" targets. Unrestricted warfare against anything that floats is not acceptable.
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.
As with land warfare, civilized countries are not supposed to set mines loose willy-nilly and are supposed to keep track of where they have laid mines. Turning loose the big, old chemical horned mines and letting them drift around is not acceptable.
80. Mines may only be used for legitimate military purposes including the denial of sea areas to the enemy.
81. Without prejudice to the rules set out in paragraph 82, the parties to the conflict shall not lay mines unless effective neutralization occurs when they have become detached or control over them is otherwise lost.
82. It is forbidden to use free-floating mines unless:
(a) they are directed against a military objective; and
(b) they become harmless within an hour after loss of control over them.
83. The laying of armed mines or the arming of pre-laid mines must be notified unless the mines can only detonate against vessels which are military objectives.
84. Belligerents shall record the locations where they have laid mines.
85. Mining operations in the internal waters, territorial sea or archipelagic waters of a belligerent State should provide, when the mining is first executed, for free exit of shipping of neutral States.
86. Mining of neutral waters by a belligerent is prohibited.
87. Mining shall not have the practical effect of preventing passage between neutral waters and international waters.
88. The minelaying States shall pay due regard to the legitimate uses of the high seas by, inter alia, providing safe alternative routes for shipping of neutral States.
89. Transit passage through international straits and passage through waters subject to the right of archipelagic sea lanes passage shall not be impeded unless safe and convenient alternative routes are provided.
90. After the cessation of active hostilities, parties to the conflict shall do their utmost to remove or render harmless the mines they have laid, each party removing its own mines. With regard to mines laid in the territorial seas of the enemy, each party shall notify their position and shall proceed with the least possible delay to remove the mines in its territorial sea or otherwise render the territorial sea safe for navigation.
91. In addition to their obligations under paragraph 90, parties to the conflict shall endeavour to reach agreement, both among themselves and, where appropriate, with other States and with international organizations, on the provision of information and technical and material assistance, including in appropriate circumstances joint operations, necessary to remove minefields or otherwise render them harmless.
92. Neutral States do not commit an act inconsistent with the laws of neutrality by clearing mines laid in violation of international law.
Why worry about mines? Take a look at the straits through which a substantial part of the world's oil must be shipped to reach the world's economy. That's why you worry about mines.