Help, what do I do when the bunker is full of water?
Club Committees can declare Bunkers an Abnormal Course Condition - Ground Under Repair which allows the player to take a free drop out of the Bunker within one club length of the nearest point of complete relief not nearer the hole. However, scores will not be Qualifying/Acceptable Scores for Handicap if more than 50% of bunkers are taken out of play.
The R&A Rules of Golf do cover the relief from Temporary Water in Bunkers under Rule 16.1c as follows:-
For free relief, the player must determine the nearest point of complete relief in the bunker, not nearer the hole, and drop ball within relief area. For penalty relief, the player must pick a reference point outside the bunker, back on the line from the flagstick and drop the ball in the relief area for penalty of one stroke. (See diagram)
If the bunker is full of water and there is no nearest point of complete relief the player may still take relief using the maximum point of relief in the bunker (in the shallowest water) not nearer the hole without penalty.