Tramp owners and owners of bulk carriers may not operate the ships themselves but may charter them out to others (the charterers). Often, these charterers may employ the ships for the duration of the charter. However, there are occasions when a ship becomes surplus to requirements, possibly temporarily, or when the main purpose of the charter was to perform a trip in one direction but the charter stipulated a round voyage. In these cases a charterer may, in turn, charter the ship out to a third party. There may thus be several “layers” of companies, giving rise to a hierarchy of people, actions and documentation. When there are only two parties involved, the shipowner and the charterer, there is no confusion as to role.When there are more levels, all of the parties and their actions and contract types may need to be distinguished one from another, something which becomes crucial in the event of a dispute.