The Convention on Contracts for the International Carriage of Goods Wholly or Partly by Sea (the “Rotterdam Rules”) is the latest convention, even though not yet in force, governing carriage by sea. ”The project is ambitious in that it is not confined to the familiar territory of the sea carrier’s liability for cargo.” ”It also covers multimodal carriage involving sea carriage, which raises difficult issues of how the new Convention will interact with existing carriage conventions such as United Nations Convention on the Contract for the International Carriage of Goods by Road (“CMR”). The convention will come into force one year after the twentieth ratification by a UN member state. Currently only two UN member states have ratified the Rotterdam Rules even though 24 states has signed the convention. However, it is not a far-fetched thought that the Convention would come into force in the coming years thus possibly considerably extending the period of responsibility for the sea carrier from today’s port-to-port approach to the Rotterdam Rules’ door-to-door approach.Despite the Rotterdam Rules’ much broader approach than its predecessors’ the main focus of the Rotterdam Rules is to regulate the carrier’s liability for lost or damaged cargo or goods as it may be named. Even though with a broader approach the new convention builds directly on the previous conventions for carriage of goods by sea: the Hague Rules, the Hague-Visby Rules and the Hamburg Rules. This thesis will focus on examining some of the implications of this possibly extended period of responsibility and potential conflicts with other conventions governing, or aiming to govern, other legs of the carriage. More precisely the thesis will examine the possible liability of the sea carrier in relation to secondary failure and evolving, un-localised damage occurring during one or more legs of carriage during a multimodal transport for which the sea carrier might become responsible even though the goods is not in the sea carrier’s custody under the Rotterdam Rules. The main goal of the thesis is to present and high light possible conflicts along the way in the text.