The construction of the expression “en route” in Marpol II

The paper that can be downloaded by opening this page and clicking here contains a discussion of the judgement of the Amsterdam District Court of 1 June 2010 regarding the question if under Annex II of Marpol a ship is allowed to leave port, or is allowed to detour, with the sole intention of discharging tank into the sea cleaning water containing residues of noxious liquid substances as meant in Annex II of Marpol.