the coast is clear
(idiomatic) There is no danger; one can freely pass through a region without risk of discovery.
Wait there, watch the back of the building, and whistle when the coast is clear.
Meg sends him to hide in a boathouse until he sees her special porch light signal and the coast is clear to rejoin her in the cabin. Source: Internet
The buzzard circles to make sure the coast is clear. Source: Internet