When a vessel
occupies a berth —
(1) in distress or
under duress;
(2) for fitting
refitting or repairs;
(3) while employed
solely on work for a religious mission; or
(4) while employed
solely as a pleasure vessel and is not engaged in trade or plying for hire,
the Company may
(provided that tonnage rates for 6 hours have been paid) grant to such vessel
a rebate of the balance of the tonnage rates otherwise payable.