Please see below white paper.
BLUF: Implementing tariffs or VERs that require goods be shipped on U.S. vessels will driving private investment in U.S. shipbuilding which will driving investment in skilled labor needed to build ships. This keeps the nation safe by provinding cheaper ships for the U.S. Navy to protect U.S. economic interest and ensure freedom of trade but also re-shores key trades back to the U.S. needed for national security and key manufacturing thus driving down cost in peripheral areas.
The key to this policy is implementing it in a gradual fashion to ensure private industy investment comes fast enough to drive production without increasing costs. This can also be used in conjunction to other tariffs that do not stipulate goods be shipped on U.S. vessels but doing so should be done carefully to ensure companies cannot get around the policy objective.