The Sand Anchor kit from Maxcons is a product that can be used on the beach or in very loose sand whilst out camping. All you have to do is bury the plate 30cm deep in the sand and then attach the spring to the guy rope.
The 50 x 150mm Steel plate is connected to a 300mm chain and a 45kg Max-compression spring.
Comes in a kit of 4 Max-Sand Anchors.