TREATIES Certain designated rules not affected. 37 Stat. 1664 . Signalling lamp. Direction-finding apparatus. Ante, p. 1156. circumstances of the case, considers it unreasonable or unnecessary to do so, or unless he is released under the provisions of paragraphs 3 and 4 of this Article. 2. The master of a ship in distress, after consultation, so far as may be possible, with the masters of the ships which answer his call for assistance, has the right to requisition such one or more of those ships as he considers best able to render assistance, and it shall be the duty of the master or masters of the ship or ships requisitioned to comply with the requisition by continuing to proceed with all speed to the assistance of the persons in distress. 3. A master shall be released from the obligation imposed by para- graph 1 of this Article as soon as he is informed by the master of the ship requisitioned, or, where more ships than one are requisitioned, all the masters of the ships requisitioned, that he or they are comply- ing with the requisition. 4. A master shall be released from the obligation imposed by para- graph 1 of this Article, and, if his ship has been requisitioned, from the obligation imposed by paragraph 2 of this Article, if he is informed by a ship which has reached the persons in distress, that assistance is no longer necessary. 5. If a master of a ship, on receiving a wireless distress call from another ship, is unable, or in the special circumstances of the case considers it unreasonable or unnecessary to go to the assistance of that other ship, he must immediately inform the master of that other ship accordingly, and enter in his log-book his reasons for failing to proceed to the assistance of the persons in distress. 6. The provisions of this Article do not prejudice the International Convention for the unification of certain rules with respect to Assist- ance and Salvage at Sea, signed at Brussels on the 23rd September, 1910, particularly the obligation to render assistance imposed by Article 11 of that Convention. ARTICLE 46. Signaling Lamp. All ships of over 150 tons gross tonnage, when engaged on interna- tional voyages, shall have on board an efficient signalling lamp. ARTICLE 47. Direction-FindingApparatus. Every passenger ship of 5,000 tons gross tonnage and upwards shall, within two years from the date on which the present Convention comes in force, be provided with an approved direction-finding apparatus (radio compass), complying with the provisions of Article 31 (17) of the present Convention.