The insured owners argued that, for unseaworthiness of this kind, there had to be not one act but a series of acts by the master (or crew) that did not come up to the required standard of skill or competence. Indeed, in one case3 a crew member called Gun Gun Jupardi ran amok, knifed four officers and crew, opened valves and sank the ship. It was not even argued that that alone was evidence enough of “disabling will”; the court sought evidence (unsuccessfully) of earlier deviant behaviour by Mr Jupardi. Something in him might just have “snapped”. In The Star Sea, however, Leggatt, L.J., who delivered the judgment of the Court of Appeal, rejected the argument. On the one hand, it was accepted that anyone can make a mistake without the conclusion being drawn that he has either “a disabling want of skill” or “a disabling lack of knowledge”.4 But the court also thought that it must be possible in certain circumstances, which the court did not define, to draw such a conclusion from a single incident that someone had a “disabling lack of knowledge”, such as had been found in the court below.5 The master’s ignorance was not