"It is unlawful for a person, in the case of a woman employed by him at an establishment in Great Britain, to discriminate against her -
"(1) ... employment is to be regarded as being at an establishment in Great Britain unless the employee does [her] work wholly or mainly outside Great Britain.
" "Great Britain" includes such of the territorial waters of the United Kingdom as are adjacent to Great Britain."
"... staff must be aboard prior to sailing time as is obvious and that means that ... they are already at their place of work, if not actually working... . To say that [Miss Fewster] was not at work and only worked from 8 o'clock is to us a distinction without a meaning. This [the period from 6 - 8 p.m.] is not to be viewed as "travelling time" as was alleged before us, this is being at work; there is no option about it, you are at work once on the vessel."