ILO 180

Art 5 paragraph 1:

The limits on hours of work or rest shall be as follows:

    (a) maximum hours of work shall not exceed : (i) 14 hours in any 24-hour period; and (ii) 72 hours in any seven-day period; or

   (b) minimum hours of rest shall not be less than : (i) ten hours in any 24-hour period; and (ii) 77 hours in any seven-day period.

Ref STCW Chapter VII, Section A-VIII/I (Fitness for Duty) column 4.

Art 5 paragraph 2:

Hours of rest may be divided into no more than two periods, one of which shall be at least six hours in length, and the interval between consecutive periods to rest shall not exceed 14 hours. Art 5 paragraph 6: Nothing in paragraphs 1 and 2 shall prevent the Member from having national laws and regulations or a procedure for the competent authority to authorise or register collective agreements permitting exceptions to the limits set out. Such exceptions shall, as far as possible, follows the standards set out but may take account for more frequent or longer leave periods or the granting of compensatory leave for watch-keeping seafarers or seafarers working on board ships on short voyages.

Art 7 paragraph 1:

Nothing in this Convention shall be deemed to impair the right of the master of a ship to require a seafarer to perform any hours of work necessary for the immediate safety of ships, persons on board or cargo, or for the purpose of giving assistance to other ships or persons in distress at sea.

Art 7 paragraph 3:

As soon as practicable after the normal situation has been restored, the Master shall ensure that any seafarers who have performed work in a scheduled rest period are provided with an adequate period of rest.

It must be noted that a ship may be detained if conditions are violated.