Related Rule
Ecuador
Practice Relating to Rule 17. Choice of Means and Methods of Warfare
Ecuador’s Naval Manual (1989) states:
The commander must decide, in light of all the facts known or reasonably available to him, including the need to conserve resources and complete the mission successfully, whether to adopt an alternative method of attack, if reasonably available, to reduce civilian casualties and damage. 
Ecuador, Aspectos Importantes del Derecho Internacional Marítimo que Deben Tener Presente los Comandantes de los Buques, Academia de Guerra Naval, 1989, § 8.1.2.1.