The White House's port cybersecurity executive order tasks the Coast Guard with monitoring the cybersecurity of vessels, facilities and harbors. Threats could target the global supply chain, national security interests and other vital systems. Rear Adm. Wayne Arguin, the Coast Guard's assistant commandant for prevention policy, discusses how the executive order will affect the service and why cybersecurity matters to the Marine Transportation System. He explains his shifting priorities as the Coast Guard assesses risks and provides cybersecurity services to ports, vessels and partners.