This questions concerns shipping logistics under the Merchanat Marine Act of 1920 as it applies to the territory of Puerto Rico.
As a hypothetical consider a manufacturing (possibly agricultural processing) plant in Honduras. Suppose the plant is American owned and suppose further the goods being made are owned or being processed for an American company. For simplicity call the company American CO. Quick question
Can American CO ship directly from a Honduran port to Puerto Rico port on any American owned and operated merchant marine ship?
By direct I mean that the American owned and operated ship does not have to traverse back to a continental US port before anchoring into Puerto Rico.