The following description comes from the event organizer.

Since 1907, visiting ships have made their way to Portland's waterfront. The City of Roses is known to be a favorite port of call for military (and non-military) visitors, as Portland's citizens thank them and make them feel welcome. The Portland Rose Festival is extremely fortunate to be one of a few U.S. Ports of Call for a courtesy visit from the U.S. Navy, U.S. Coast Guard, and Royal Canadian Navy. Their arrival commemorates a relationship with the Navy that has lasted more than 100 years, and over 80 years of visiting Portland during the Rose Festival. It is a significant commitment by the Navy to make Rose Festival Fleet Week one of the premier Fleet Week events in the country.