I remember Taff Warren (ex VC10 Capt) telling me story of his Nav on a route somewhere,
Conversation along these lines....
Nav::: Capt, turn left 20degs
Capt:: ok....
time delay unknown...
Nav::: Capt, turn right 20degs
Capt:: ok.....
further time lapse.....
Nav::: Capt, turn left 20degs
Capt:: Surely we are back on same course Nav...
Nav:: Affirm !!
Capt: Why the detour ??
Nav:: i dropped me dinner on the bloody chart..!!!
Ops room fell about larfing big time....