Off-duty periods include not only such periods as shore leave but
also generally those hours spent by a seaman on the vessel outside his
watch or normal or regular working hours and his standby periods during
which hours he is not required to perform and does not perform work of
any kind but is free to utilize his time for his own purpose. The fact
that during such off-duty periods the employee is subject to call in
case of emergency situations affecting the safety and welfare of the
vessel upon which he is employed, or of its passengers, crew, or cargo
or for participation in life boat or fire drills will not render such
off-duty periods, excluded by employment agreement applicable to the
employee, ``hours worked''. Responding to such calls, however, as well
as the performance of work in response thereto constitute compensable
work time. For further and more detailed discussion on what generally
are regarded as ``hours worked'' under the Act, see part 785 of this
chapter.