just about every where except dry sand. It really depends a lot on the dynamics of the beach that you hunt and your timing. What are the characteristics of the beach? Does it stay shallow or get deep quickly? What is the prevalent current? How much tide? Ocean waves or bay waves? Lake/pond? Observe how the beach sand moves and where the people congregate.
Most of the horse-play that takes place on the beach is in a specific area, in waist deep water. The width of the area will vary due to the tide but that area is where I find the most gold. With time, it moves up towards the beach.
I also look in the wave trough area. On some beaches, the waves will create a trough just where the waves break on the sand. Found 3 heavy gold rings in that area.
If you are a water wader, you want the sand to get put up on the beach and if you are a wet/dry sand hunter, you want that sand taken out. A major storm can do either and change your fortunes overnight. Then you have to "make hay while the sun shines", so to speak, because the sand will move as soon as the next weather system comes through.