4.24 Prevention and Control of Water Ingress, etc.:

(1) All watertight doors shall be kept closed during navigation provided that-

• (a) they may be opened during navigation as specified in subsections (3) and (4);

• (b) watertight doors of a width of more than 1.2 metres in machinery spaces as permitted by section 4.15 (10) may only be opened in the circumstances detailed in that regulation; and

• (c) any door which is opened in accordance with this paragraph shall be ready to be immediately closed.

(2) Watertight doors located below the bulkhead deck having a maximum clear opening width of more than 1.2 metres shall be kept closed when the ship is at sea, except for limited periods when absolutely necessary as determined by the Administration.

(3) A watertight door may be opened during navigation to permit the passage of passengers or crew, or when work in the immediate vicinity of the door necessitates it being opened provided that the door must be immediately closed when transit through the door is complete or when the task which necessitated it being open is finished.

(4) Certain watertight doors may be permitted to remain open during navigation under the following conditions-

• (a) only if considered absolutely necessary; that is, being open is determined essential to the safe and effective operation of the ship’s machinery or to permit passengers normally unrestricted access throughout the passenger area;

• (b) such determination shall be made by the Administration only after careful consideration of the impact on ship operations and survivability; and

• (c) a watertight door permitted to remain thus open shall be clearly indicated in the ship’s stability information and shall always be ready to be immediately closed.

(5) Portable plates on bulkheads and power-operated sliding doors permitted in machinery spaces in accordance with section 4.15(10) shall be subject to the following provisions-

• (a) portable plates shall always be in place before the ship leaves port, and shall not be removed during navigation except in case of urgent necessity at the discretion of the master;

• (b) the necessary precautions shall be taken in replacing portable plates to ensure that the joints are watertight; and

• (c) power-operated sliding watertight doors permitted in machinery spaces shall be closed before the ship leaves port and shall remain closed during navigation except in case of urgent necessity at the discretion of the master.

(6) Watertight doors fitted in watertight bulkheads dividing storage between deck spaces in accordance with section 4.15(9) shall be closed before the voyage commences and shall be kept closed during navigation; the time of opening such doors in port and of closing them before the ship leaves port shall be entered in the logbook.

(7) Gangway, stores and fuelling ports fitted below the bulkhead deck shall be effectively closed and secured watertight before the ship leaves port, and shall be kept closed during navigation.

(8) The following doors, located above the bulkhead deck, shall be closed and locked before the ship proceeds on any voyage and shall remain closed and locked until the ship is at its next berth-

• (a) doors in the shell or the boundaries of enclosed superstructures;

• (b) garage doors fitted in positions as indicated in paragraph (a) above;

• (c) doors in the collision bulkhead; and

• (d) other shell openings forming an alternative closure to those defined in the above paragraphs (a) to (c) inclusive.

(9) Notwithstanding the requirements of paragraphs 8(a) and (d) above, the Administration may authorise that particular doors can be opened at the discretion of the master, if necessary for the operation of the ship or the embarking and disembarking of passengers and appropriate recreational activities when the ship is at safe anchorage and provided that the safety of the ship is not impaired.

(10) The master shall ensure that an effective system of supervision and reporting of the closing and opening of the doors referred to in subsection (8) is implemented.

(11) The master shall ensure, before the ship proceeds on any voyage, that an entry in the log-book is made of the time of the last closing of the doors specified in subsection (13) and the time of any opening of particular doors in accordance with subsection (14).

(12) Hinged doors, portable plates, sidescuttles, gangway, stores loading and bunkering ports and other openings, which are required by these regulations to be kept closed during navigation, shall be closed before the ship leaves port and the time of closing and the time of opening (if permissible under the Code regulations) shall be recorded in such log-book as may be prescribed by the Administration.

(13) Where in a between-decks, the sills of any of the sidescuttles referred to in section 4.16(4) are below a line drawn parallel to the bulkhead deck at side and having its lowest point 1.4 metres plus 2.5% of the breadth of the ship above the water when the ship departs from any port-

• (a) all the sidescuttles in that between-decks shall be closed watertight and locked before the ship leaves port;

• (b) they shall not be opened before the ship arrives at the next port;

• (c) in the application of this paragraph the appropriate allowance for fresh water may be made when applicable;

• (d) the time of opening such sidescuttles in port and of closing and locking them before the ship leaves port shall be entered in such log-book as may be prescribed by the Administration; and

• (e) for any ship that has one or more sidescuttles so placed that the requirements of this subsection would apply when it was floating at its deepest subdivision draught, the Administration may indicate the limiting mean draught at which these sidescuttles will have their sills above the line drawn parallel to the bulkhead deck at side, and having its lowest point 1.4 m plus 2.5% of the breadth of the ship above the waterline corresponding to the limiting mean draft, and at which it will therefore be permissible to depart from port without previously closing and locking them and to open them at sea on the responsibility of the master during the voyage to the next port; in tropical zones as defined in the International Convention on Load Lines in force, this limiting draught may be increased by 0.3 metres.

(14) Sidescuttles and their deadlights which will not be accessible during navigation shall be closed and secured before the ship leaves port.

(15) If stores are carried in spaces fitted with sidescuttles then those sidescuttles and their deadlights shall be closed watertight and locked before the stores are shipped and such closing and locking shall be recorded in such log-book as may be prescribed by the Administration.

(16) When a rubbish-chute, etc., is not in use, both the cover and the valve required by section 4.16(10)(b) shall be kept closed and secured.