NECESSITY IN THE CONTEXT OF MARITIME ADVENTURES
The law on salvage103 is highly complex but, to the extent that it involves restitution, it can be considered to be founded on the principle of necessity. Although the doctrine of maritime salvage can be analysed, at least to some extent, by reference to the unjust enrichment principle, it is not possible to justify the award of restitutionary remedies in terms of an absence of a freely exercised choice to intervene on the part of the salvors, unlike the other grounds of restitution which are founded on the principle of necessity.
This is particularly because most salvors today are professionals who do not find themselves in circumstances of necessity but actually seek out such emergencies, and so would be characterized as volunteers who are acting officiously from motives of self-interest. Indeed, in Falcke v Scottish Imperial Insurance Co10 Bowen LJ specifically excluded maritime salvage from the principle that liabilities are not to be forced upon people behind their backs. The salvage award which such salvors receive is primarily justified by public policy  to encourage salvage services to be provided.