Because the owner may, when he has used due diligence to furnish a seaworthy ship, contract against the obligation of seaworthiness, it does not at all follow that when he has made no contract to so exempt himself he nevertheless is relieved from furnishing a seaworthy ship, and is subjected only to the duty of using due diligence. To make it unlawful to insert in a contract a provision exempting from seaworthiness where due diligence has not been used, cannot by any sound rule of construction be treated as implying that where due diligence has been used, and there is no contract exempting the owner, his obligation to furnish a seaworthy vessel has ceased to exist. The fallacy of the construction relied upon consists in assuming that because the statute has forbidden the shipowner from contracting against the duty to furnish a seaworthy ship unless he has been diligent, that thereby the statute has declared that without contract no obligation to furnish seaworthy ship obtains in the event due diligence has been used.
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The exemption of the owners or charterers from loss resulting from "faults or errors in navigation or in the management of the vessel," and for certain other designated causes, in no way implies that because the owner is thus exempted when he has been duly diligent that thereby the law has also relieved him from the duty of furnishing a seaworthy vessel. The immunity from risks of a described character, where due diligence has been used, cannot be so extended as to cause the statute to say that the owner when he has been duly diligent is not only exempted in accordance with the tenor of the statute from the limited and designated risks which are named therein, but is also relieved as respects every claim of every other description from the duty of furnishing a seaworthy ship.
In the Wildcroft, 201 U. S. 378, a cargo of sugar was injured by an opening of a valve in the ship's side in such a manner that water got into the cargo. The vessel was in all respects seaworthy at the beginning of the voyage, and the court held that having discharged the duty of providing a seaworthy ship the vessel was relieved from liability arising out of an unseaworthy condition, which devolved after the beginning of the voyage and without the fault of the owners. It was emphasized, however, following the case of the Southwark, 191 U. S. 1, that the burden is upon the owner of a vessel
to show by reasonable and proper tests that the vessel was seaworthy and in a fit condition to receive and transport the cargo undertaken to be carried and that if, by failure to adopt such tests and furnish the required proofs, the question of the ship's seaworthiness was left in doubt, that doubt must be resolved in favor of the shipper, because the vessel owner had not sustained the burden cast upon him by the law to establish that he had used due diligence to furnish a seaworthy vessel.
As it emerges from the interpretation of the courts, the effect of the Harter Act seems to amount to this:
The act says to the shipowner:
1. You may make a valid bargain by which you will be exempted from liability, if you use due diligence to make the ship seaworthy at the beginning of the voyage, and some defect develops which eluded your diligence. Unless you make such a bargain, your obligation to provide a ship which is seaworthy at the commencement of the voyage is absolute, and, in no event, can you bargain to relieve yourself from using due diligence.
2. You cannot bargain away your duty and obligation to use due diligence to see that your vessel is maintained in seaworthy condition during the voyage, but you may, if you like, bargain that if you use due diligence and your ship nevertheless become unseaworthy, you shall be relieved from responsibility for damage to cargo on that account.
3. If you use due diligence to employ a competent master and crew and their skill in navigation fails or the ship encounters perils of the sea and accident happens to the cargo you are not responsible for the damage. Your exemption from responsibility in this case is given by the statute and you do not need to bargain for it.