Red and Yellow stakes

play a ball from where your last shot was played, or
drop a ball any distance behind the water hazard keeping a straight line between the hole, the point where the ball last crossed the margin of the water hazard and the spot on which the ball is dropped.

If your ball is in a lateral water hazard (red stakes and/or lines), in addition to the options for a ball in a water hazard (see above), under penalty of one stroke, you may drop within two club-lengths of, and not nearer the hole than:

the point where the ball last crossed the margin of the hazard, or
a point on the opposite side of the hazard equidistant to the hole from the point where the ball last crossed the margin.

Ball Unplayable

If your ball is in a water hazard and you do not wish to play it as it lies, you must proceed under the water hazard Rule - the unplayable ball Rule does not apply. Elsewhere on the course, if you believe your ball is unplayable, you may, under penalty of one stroke:

play a ball from where your last shot was played, or
drop a ball any distance behind the point where the ball lay keeping a straight line between the hole, the point where the ball lay and the spot on which the ball is dropped, or
drop a ball within two club-lengths of where the ball lay not nearer the hole.

If your ball is in a bunker you may proceed as above, except that if you are dropping back on a line or within two club-lengths, you must drop a ball in the bunker.

Ball Lost or Out of Bounds; Provisional Ball

Check the Local Rules on the score card to identify the boundaries of the course. These are normally defined by fences, walls, white stakes or white lines.

If your ball is lost outside a water hazard or out of bounds you must play another ball from the spot where the last shot was played, under penalty of one stroke, i.e. stroke and distance.

You are allowed 5 minutes to search for a ball. If it is not found within 5 minutes it is lost.

If, after playing a shot, you think your ball may be lost outside a water hazard or out of bounds you should play a provisional ball. You must announce that it is a provisional ball and play it before you go forward to search for the original ball.

If the original ball is lost (other than in a water hazard) or out of bounds, you must continue with the provisional ball, under penalty of one stroke. If the original ball is found in bounds within 5 minutes, you must continue play of the hole with it, and must stop playing the provisional ball.

Playing the Ball

Play the ball as it lies. Don’t improve your lie, the area of your intended stance or swing, or your line of play by:

moving, bending or breaking anything fixed or growing, except in fairly taking your stance or making your swing, or
pressing anything down (Rule 13-2).

If your ball is in a bunker or a water hazard, don’t;

touch the ground (or the water in a hazard) with your hand or club before your downswing, or
move loose impediments (Rule 13-4).

If you play a wrong ball (i.e. stray ball or ball being used by another player):

in match play you lose the hole
in stroke play you incur a two-stroke penalty, the strokes made with the wrong ball do not count and you must correct the mistake by playing the correct ball (Rule 15-3).