1. Every ship to which this Convention applies shall be sufficiently, safely and efficiently manned, in accordance with the minimum safe manning document or an equivalent issued by the competent authority.
2. When determining, approving or revising manning levels, the competent authority shall take into account:
a. the need to avoid or minimize, as far as practicable, excessive hours of work, to ensure sufficient rest and to limit fatigue; and
b. the international instruments identified in the Preamble.