PURPOSE: To automatically show a signal for rescue when a person has dropped into the sea, by storing a flag with a weight in a cylinder so that the flag can be moved down by opening a lid.

CONSTITUTION: A cylinder 1 is secured on the upper part of a mast 5. A flag 7 is stored in the cylinder 1 and the cylinder is closed at the bottom with a lid 2. For signaling, an electrical current is caused to flow through an electromagnetic contactor electrode 3 from a time limit contact 4 to disengage a pin 8 out of a hole 9 to open the lid 2 down. As a result, the flag 7 is moved down out of the cylinder 1 and spread by a weight 6. The flag 7 is thus displayed as a signal to other ships for rescue.