tax. Even if the Panamanian company moved its headquarters from Miami, it would likely still be considered engaged in a trade or business in the United States because it has a continuous and systematic presence in the United States. For example, with 90% of customers being U.S. citizens or residents and docking at U.S. ports daily, these cruise ships would be perceived as if they still had a true principal place of business. Treating such income as originating in the United States and effectively connected with a U.S. trade or business would make such income subject to U.S. taxes at the same rate as other income, e.g. the corporate income tax rate is 35 percent. Along with this tax, Senator Rockefeller's bill called for a 5 percent excise tax, which would be used to finance the infrastructure that ships benefit from. The Rockefeller bill would impose this excise tax on gross revenues from cruises “embarkating or disembarking passengers in the United States.” Generally, cruises where the majority of passengers embark or disembark in the United States would have all gross revenues from that trip subject to excise tax. However, for cruises that call at a U.S. port, but do not embark or disembark the majority of passengers in the United States, only half of the gross revenue from that voyage would be subject to the tax. According to Senator Rockefeller, the excise tax is similar to passenger taxes in the aviation industry and the gasoline tax for motor vehicles.