A player has five minutes to look for a ball before it is deemed to be lost.
The player must then add a one-stroke penalty to the score.
They must then play a second ball as near as possible to the spot from where the original shot was played (not where the ball was thought to be lost).
An exception to this is when the ball is lost in a water hazard.
Then the ball may be dropped behind the hazard, keeping the point at which the ball last crossed the margin of the hazard between the flag and the spot where the ball is dropped.
There must be 'reasonable evidence' to suggest the ball is lodged in the water hazard in order for it to be deemed lost in it.
Otherwise it must be classed as a lost ball and the player returns to the original spot.