Why is it that some beaches have murky waters and others have beautiful, crystal-clear waters?

OK, so this may sound like a silly question, but I need to know. Why is it that some beaches have calm, crystal-clear waters and others don’t? I mean, you take a beach on the Atlantic Coast and the water is a dark, murky brownish-green color, and of course, there are the waves.. Then you take a beach in the Virgin Islands and it’s crystal clear, very blue, and the waters are pretty calm. I’m assuming it has something to do with the movement of the water, but I’m not sure. Could someone elaborate on this for me? Thanks.

Water’s in the Caribbean (and warmer climates in general) are basically “dead”. Water in more temperate climates have a lot of plant life. The chlorophyll is what causes the greenish tinge.

Beautiful Crystal
Beautiful Crystal
Beautiful Crystal