A sky view can help with many things.
This article is about a pilot project to use drones for container screening as part of the normal customs process, Project looks into whether drones could help with port security
While this is just another example for how drones might add value, I think the more important use on a port would be for general observation during security events or accidents. Ports don't have aircraft like planes or helicopters, so aerial observation is a luxury in today's security environment. Back when I was a director of security for the Port of Tacoma, I sought to use Port Security Grant Program funds to purchase a drone. There was no interest to do so from port management.
My point was that a drone could also be used for marketing the port's business interests by showcasing properties, routes, etc. Still — no interest.
Several years ago, I attended a Northwest Ports meeting and I asked the question, "Does anyone have a drone?" Surprisingly, a number of small ports raised their hands. They were using the drones for marketing purposes. It just goes to show that you don't have to be big to be innovative.