In my infant's school we had a lethal set of rough concrete play equipment fixed to the playground. One such piece of apparatus was the traditional 70's concrete boat. It was divided in the middle by two planks of wood. We designated one side as 'wee' and one as 'poo'. The game generally consisted of getting someone in either half and then running around the boat shouting 'you're in poo/ wee' and laughing at them. Variation was to all trot around on the edge of the boat or on the planks trying to push each other into the wee or poo....and then shout at each other.