The Jones Act (AKA Merchant Marine Act of 1920) is US Federal Statute that among other things, regulates maritime commerce in US Waters and between US Ports. Section 27 of the Jones Act requires all goods transported by water between US ports to be carried US flagged ships, constructed in the US and owned by US Citizens and Crewed by US Citizens and US Permanent Residents.
That means that a cargo ship filled with goods from China can only make one stop in the U.S. at a time. It can’t stop in Hawaii to exchange goods before heading to Los Angeles. For example, a Chinese-flagged ship (even if built in the US, crewed by US citizens, and owned by US citizen) could not stop in Hawaii on its way to a West coast US Port. It would have to unload cargo on the West coast and have a Jones Act compliant ship sail form the West coast US port to deliver that cargo to our Hawaii US Port.
A 2014 Hawaii State Task Force has supported Jones Act exemption for Hawaii. The focus of the study was on Hawaii having only two petroleum refineries and the effect of one or both shutting down. The task force report briefly touches on the cost-of-living issue of the Jones Act in Hawaii and endorses a more modest exemption of US-built ships, the other Jones Act conditions would still apply.
Hawaii has tried before to pressure US Congress to exempt the Jones Act for Hawaii.