This clause corresponds to three clauses in the original version of Supplytime, and its three sub-clauses deal with different situations.
Sub-clause (a) deals with the position if the vessel has to interrupt the charterers’ work to rescue people whose lives are in danger. It is obvious that the vessel must be permitted to depart for this purpose (although this may need to be spelled out to charterers whose background is not in shipping but in upstream oil and gas or energy generation). But it is not obvious that the vessel must remain on hire while she is absent for this reason, and charterers may want the balance of the sub-clause to be redressed by saying that the vessel is not permitted to depart unless in the reasonable judgment of the master she is needed to assist in a rescue, and if the vessel is nevertheless required by the local authorities to stand by a casualty then she will be off-hire.
Sub-clause (a) will inevitably continue to be of real importance. However, sub-clause (b) which deals with the vessel departing when not life but only the property of third parties is in danger, is likely hardly ever to be put into effect, because in almost all cases the charterers will (not unreasonably) refuse consent for the vessel to interrupt her work in order to try to earn a salvage award. Sub-clause (c), also, is likely in practice to apply only rarely because under Supplytime this sub-clause applies only in relation to a ship or offshore installation which the chartered vessel was serving before the need for salvage assistance arose, and because admiralty law severely restricts the circumstances in which a vessel which was engaged under contract to provide service to another ship (or other item of property) can be treated as no longer providing service under the contract but instead as giving salvage assistance.
The discussions of the details of sub-clauses (b) and (c) are only included for the use of those who may find themselves needing to apply the wordings with regard to the division of a salvage award under (b) or the special terms under (c). With regard to sub-clause (c), in particular, the discussion has to deal with points of salvage law (such as the separate rights of the master and crew of a salving vessel) which are not normally relevant in an age where salvage is normally undertaken by professional salvors (whose crews are employed on articles which dispose of their separate rights to a salvage award).
The special terms under sub-clause (c), which are to displace the knock-for-knock arrangement while the vessel is giving salvage assistance to property belonging to the charterers’ side of the contract, may be justified by the thought that the risks of salvage work go beyond what the owners would have expected that the Supplytime contract would involve. However, those who would make an exception to the knock-for-knock in case of gross negligence or wilful misconduct by those in charge of the other party’s operations, may justify this exception by exactly the same thought, that a party may be expected to accept the risk of simple negligence by the other party’s employees, but if those in charge of the other party’s operations wilfully or stupidly depart from good industry practice, this goes beyond what a party may be supposed to have accepted. Logically, those on the shipowners’ side of the business who advocate a knock-for-knock without any exception for wilful misconduct, should also be willing to give up these special terms.