rules help

There are two significant decisions that should answer your question.

As it was not unreasonable to expect that your opponent's ball could be affected by the sand splash from your stroke I would suggest that 18-3b/1 applies rather than 18-1/8.

See the last paragraph of 18-3b/1.

18-1/8

Ball Moved by Stone Dislodged by Partner's or Opponent's Stroke

Q. In match play, a player made a stroke and dislodged an embedded stone. The stone struck his partner's or an opponent's ball which was lying about four yards ahead and moved it. What is the ruling?

A. The player is not deemed to have caused the other ball to move.

In playing his ball as it lies, the player could not, through reasonable care, have avoided dislodging the stone through his stroke. Moreover, in these circumstances it was not reasonable to expect the player to ask the partner or opponent to lift his ball under Rule 22-2 because the player could not have reasonably foreseen that his stroke would dislodge the stone ultimately leading to the movement of the opponent's ball.

Accordingly, the player's actions are deemed not to have caused the movement of the other ball, and Rules 18-2a(i) and 18-3b do not apply. The stone is deemed to have caused the movement of the other ball and, as the stone is an outside agency, Rule 18-1 applies. The player incurs no penalty, and the partner or opponent must replace his ball.

Related Decision:

· · 18-3b/1 Ball Moved Accidentally by Opponent in Playing His Own Ball.

18-3b/1

Ball Moved Accidentally by Opponent in Playing His Own Ball

Q. In singles match play, A's ball is lying close to B's. It is B's turn to play. Although B has the right under Rule 22-2 to require A to mark the position of and lift his ball, he fails to do so. In making a stroke at his ball, B causes A's ball to move. What is the procedure?

A. B incurs a one-stroke penalty under Rule 18-3b for having caused A's ball in play to move. A must replace his ball; if A's lie has been altered, Rule 20-3b applies.

This ruling differs from that in Decision 18-1/8 , because it was reasonably foreseeable that B's stroke could cause A's ball to move, and because B could, through the exercise of reasonable care, have avoided causing A's ball to move by having A's ball lifted prior to his stroke.

When you found your opponents ball interfering with your stroke, you should have requested that the opponent mark their ball and remove it.  If you honestly didn't think the ball would interfere and did not intentionally try to alter your opponents lie, there is no penalty.  Your opponent should try and place his ball on or as near the original lie as possible, and in a bunker or hazard, recreate the lie as accurately as possible; whether it be plugged, embedded, or sitting gently on top.  You may maintain the bunker (rake the area smooth) before they place their ball.  Yes, they push it down if it was embedded before, and right next to the lip if that's where it was.  They do not drop or take relief, but there is no penalty on them---you if you did it on purpose.

Did you read the two decisions above?