 The Passage is approximately in length from MacDonalds Shoal (near Janvrin Island) to Ouetique Island near D'Escousse with depths varying from 3 to 20 metres.The Passage is well-buoyed and marine interests should be aware that eastbound vessels leave the green buoys to starboard while making their way towards St. Peter's.Initially crossed by two ferries, (one from the present location of the bridge and one from Grandique Point to Grandique Ferry), construction of a swing bridge began in 1916 and was completed in 1919, connecting Isle Madame to Cape Breton.