It is most unlikely that a charterparty would be agreed without any additional clauses, known as rider clauses, being added. These clauses always take precedence over the printed ones in the Charterparty. Although these clauses may be drafted by the owner or the shipbroker to cover a particular situation, there are a number of recognized clauses available. The advantage of using such clauses is that they are well known and their meaning is usually understood. This presents less risk of a dispute than would be the case if the clause has to be specially drafted. INTERTANKO provide a book containing a large number of such clauses. The use of ‘recognised’ clauses is more common with tanker chartering than dry cargo chartering. An important use for these clauses is in a situation where additional costs that are not mentioned in the charterparty document are incurred. An example is in American Ports loading bulk cargo where the owner will want to include ‘Dumping and Trimming’ costs to be paid by the charterer. With older ships, the cargo had to be trimmed, that is levelled off, before the ship could proceed to sea. Although it is not as important now, these costs are frequently included in the port costs and it needs to be spelt out who is to pay for them. Other common examples are for weather delays e.g. the Conoco Weather Clause.