Confiscation of conveyances covers concealment, smuggling, unauthorized unloading, and missing imported goods under customs law. Conveyances are liable to confiscation if they are adapted for concealing goods, used to prevent seizure by throwing goods overboard or destroying them, fail to stop or land when required, unload export goods without permission, or are found with imported goods missing without explanation. A conveyance or animal used in smuggling is also liable to confiscation unless the owner proves lack of knowledge or connivance, and in hire cases an option to pay a fine in lieu of confiscation may be available, based on market price at seizure.