Make a Sand Castle
Start with a five-gallon bucket with its bottom cut out. Set it down in the sand and drop in four to five inches of fine sand. Add enough water so all the sand gets wet, but not so much that water runs out the bottom. Tap the sides of the bucket with the palms of your hands to set the sand. From this point on, add water first, then sand, alternating layers. You should keep a couple of inches of water on the top at all times. When the bucket is full, tap the sides again and slide the bucket off. You should now have a solid cylinder of compacted sand ready for carving.