Coast is clear

[fredpuli47]

How old is the expression 'the coast is clear ' meaning it's safe to do something because there's nobody about ? What did it refer to at first? For example, it sounds as though it was said by smugglers to mean that there were no excise men about and the coast was clear to land contraband,or it may be a sailors' expression to mean that there is clear weather and so coastal navigation and getting into harbour will be untroubling..

[Quizmonster]

The earliest usages, from the 1500s - eg in Shakespeare - referred to the coast being clear of enemies who might either prevent embarkation of friendly forces from OUR own shores or prevent the landing of our forces on THEIR shores. In either case, there are no baddies about to bar what we intend doing.