Political Restrictions in Maritime
Dimensions and climate are not the only restraints on where a ship may trade, sadly the dislike some countries have for another is such that, having been to one, the ship may not be permitted to enter the ports of another.
Problems in this respect include countries such as Israel. This is mainly because a vessel trading to Israel will be blacklisted by Arab countries from trading to their ports, obviously a major restriction in view of the number of Arab countries involved and the fact that the vessel could be restricted from transit of the Suez Canal.
Similarly, Owners and operators of ships that have called at Cyprus ports under Turkish control can expect to be prevented from calling at Greek ports as a result of government policy.