What are the rules reguarding a golf ball landing in a puddle of water in a sand trap?

Answer 1

This is known as casual water. You are allowed to take relief, you do so as follows, drop the ball anywhere in the bunker, no nearer the hole. You do so unless the course manager has designated the bunker Ground Under Repair, in which case you get a free drop out of the bunker.

Answer 2

No one has answered my question, but here is what I found so far. Seems to me this would be like losing the ball in the casual water.

What to do if your ball is lost in the sand.

If your ball is buried so deep in a bunker that it is lost from sight, what can be done to find it? More than you might think. Rule 12-1 allows you to rake the sand or probe it with a club, or anything else, as a way of uncovering a "lost" ball.

In your search, you are allowed to remove enough sand so that part of the ball (just enough to see that it is a ball) is visible. If an excess of sand is removed, or if the ball is moved in the process of searching for it, there is no penalty. Replace the ball if moved and, in either case, re-cover it with sand. (You are allowed to then remove some sand to leave part of the ball visible.)

If, once you've found it, you don't think you can extricate the ball from the lie, you can declare it unplayable and take a one-stroke penalty. If you drop within two clubs-lengths no closer to the hole or on a line behind the ball, you must drop in the bunker; you can also return to the spot of your previous stroke. If the ball is not found, you must take a stroke-and-distance penalty for a lost ball.