So this spot was quite unusual, with a thick layer of sand on top. It acted like quicksand when I walked upon it, moving and turning to liquid... until I really sank through it. But underneath that layer, which measured about 10 cm, was only soft creamy mud that didn't get you stuck at all. Although it was a nice spot, I was quite disappointed, as I've always dreamed to get into some real quicksand ! Does anyone have some experience with that kind of mud ?