Raise The Flag?

What does this picture depict? It appears that a fleet flag is higher than the American flag! The man on the right looks to be raising a pennant with the number 1223. Is this a ship number? The man on the left seems to be to be raising a Union Jack. Does any of the activity correspond with the passing ship? The photo was taken at Belle Isle in the 1960's. The ship is the Shenango II.