Drilling in sand presents special problems. I've heard from quite a few beach and coastal residents who have experienced problems. On the one hand, drilling in sand is easy. It takes no time at all to wash down 10 or even 20 feet of pipe. On the other hand you are guaranteed to get stuck down around the 20 foot mark if you don't take some action to avoid it. The sand collapses on the drill pipe almost as quick as you drill/wash your way down through it. After a while, the weight of sand on your drillpipe makes the drillpipe impossible to move.