Freely translated from the Latin in rem simply means ‘against a thing’ to differentiate it from in personam – against a person.  The big advantage of proceeding against the ship is that it is not necessary to chase all over the world looking for the owner and then discovering that he lives in a country where taking legal action against him would be expensive and difficult.  By taking action against the ship it is not necessary even to name the owners but the circumstances which permit action in rem are limited and the best way to envisage these is to see it restricted to debts owned by the ship.  It is by no means a new procedure and the way it operates varies from country to country although steps continue to be taken in an endeavour to produce a fully recognised international convention. The procedure for arrest is similar in most countries although the courts and officials concerned may vary. There are certain countries where the procedures for arresting a vessel are particularly straightforward including The Netherlands and South Africa for example. In the UK there is a special section of the judicial system dealing with maritime affairs and the act of arresting a ship is controlled by the Admiralty Marshall.  The days are gone when the Admiralty Marshall himself nailed a writ to the ship’s mast; things today are more civilised but the effect is just the same.  An officer of the Customs, who act as agent for the Admiralty Marshall, will board the ship and attach a notice with adhesive tape to a prominent place inside the bridge.  Once that is done no one may move the ship at all without risking a charge of Contempt of Court for which the penalties still include imprisonment.  It is even very difficult simply to move the ship off the berth to allow the terminal operator to use the jetty for other ships.  Incidentally the arresting officer has the right to remove some vital part of the ship’s machinery to ensure its immobility if there is any risk in his judgement of the ship departing despite the risk of penalties.