(1) Subject to subsection (2) where any of the requirements of section 476M or 476N are contravened in the case of any master, that master, and any other person, being that master's employer or a person to whose orders that master is subject, who caused or permitted the contravention, commits an offence.
(2) A person is not liable under this section where he or she can prove—
(a) that the contravention was due to an unavoidable delay in the completion of a voyage arising out of circumstances which he or she could not reasonably have foreseen; or
(b) in the case of a person other than the master that the contravention was due to the fact that the master had for any particular period conned a vessel or been on duty otherwise than in the employment of the person charged or, as the case may be, otherwise than in the employment in which he or she was subject to the orders of the person charged, and that the person charged was not, and could not reasonably have become, aware of that fact.
General