The majority of maritime commercial transactions involve the carriage of goods. The primary document is the bill of lading, which is basically a contract of carriage. In 1936 the Carriage of Goods by Sea Act (COGSA) was passed in the United States, only applies to foreign trade and is limited to the time the cargo is loaded and discharged from the vessel. COGSA was in implementation of the Hague Rules, which sought to ensure a seaworthy ship and the proper care of goods. COGSA was also enacted to cover encompass the international sphere of uniform liability rules governing domestic voyages found in the Harter Act of 1893. It covers only the period of time between the times the goods are loaded on the ship and when they are discharged from the shop. The main point of the Act was to prevent ship owners contracting out of the duty to properly care for the vessel and the cargo onboard.
Two terms for dispute in maritime law are in personam and in rem. The in personam suit is typical of other forms of law, but in rem is nearly exclusive to admiralty jurisdiction and is basic to the maritime lien. In maritime law an aggrieved party has a property interest in the vessel or other tangible item involved in the amount of the accrued liability and this right is a maritime lien. In rem is an action directly against the vessel bearing the lien. An in rem can only be brought to a federal court as a court of admiralty. The in personam can be brought to federal or at common law in state courts.
Particular to marine insurance and general insurance law are the terms condition and Warranty. In English law a condition is a portion of the contract that is fundamental to the performance and if breached voids the entire contract. A warranty is not essential to contract fulfilment and will not constitute a breach. In Marine insurance law the terms are reversed and refer to implied warranties such a seaworthy vessel and those specifically expressed in writing. Warranties can be excused upon a change of circumstance such as a deviation or a situation that frustrates the contract. Expressed warranties do not exclude implied warranties, that is, it is assumed that the ship is seaworthy even though the fact is not stated in shipping documents.
The Marine Insurance Act 1906 has several very important sections that include foremost section 4 which states that a policy without insurable interest is void and section 17; Insurance is uberrimae fides. Marine contracts are based on good faith or the truthfulness of both parties and if that does not occur then the contract maybe voided.