I'm thinking more like 30 yards. It's far enough that you should be a moderately good swimmer or use the safety line which runs from from the dingy line onto the beach, i.e., you grab it and pull yourself in. But.... that line has enough marine growth that you might well get cut up using it. It would sure be nice if on the end of Devils bay they would have a dingy lane to drop people off. But wishful thinking.

Baard mentions 25 balls - that sounds right to me.