What is the effect if unseaworthiness is unknown to the owner of the cargo?

It is immaterial in ordinary marine insurance and may not be used by him as a defense in order to recover on the marine insurance policy. It becomes the obligation of a cargo owner to look for a reliable common carrier, which keeps its vessels in seaworthy conditions. The shipper may have no control over the vessel but he has control in the choice of the common carrier that will transport his goods. (Roque v. IAC, G.R. No. L-66935, Nov. 11, 1985)