We were heading back from Grosse Point yesterday afternoon when I came across a 3 - 4" PVC Pipe sticking out of the water. No lights, No color, just white. It had a cleat and some yellow rope attached to it. It is not marked on my chart, and only stuck out of the water about 2 feet. Does anyone know what it is there for? I missed it by about 30 feet as the waves were blocking it and it was hard to see. This could be a bad situation for someone at night and for someone during the day if they are not paying attention.