The obligation to provide a seaworthy ship is core in the carriage of goods by sea, including in charterparties, where the contract of carriage is between a shipowner and a charterer. As seaworthiness is not usually defined in modern standard form charterparties, the meaning of the concept has to be ascertained from cases decided at common law. In charterparties, whether time, voyage or bareboat, it is normal for the obligation to be laid down in express wording, often describing the standard required as one of due diligence. Alternatively, such a due diligence standard is imported into the charterparty by means of a paramount clause, bringing into the charterparty the relevant terms of the Hague or Hague-Visby Rules or some domestic statute giving effect to those Rules.