What are types of action in man overboard ?

There are three situations , namely:

 Immediate action:

The person overboard is noticed from the bridge and action is taken immediately.

 Delayed action:

The person is reported to the bridge by an eyewitness and action is initiated with some delay. 

Person missing action:

The person is reported to the bridge as missing. When the possibility exists that the person has fallen overboard the crew must attempt to recover the individual as soon as possible.

ANAND GAUTAM