The first dog watch..

Dog watch, in marine terminology, is a period of work duty or shift, between 16:00 and 20:00 (4 pm and 8 pm). This period is split into two, with the 'first' dog watch from 16:00 to 18:00 (4 pm to 6 pm - When this image was taken) and the 'last' dog watch from 18:00 to 20:00 (6 pm to 8 pm). Each of these watches is half the length of a standard watch.